Touch display device, driving circuit, and driving method

ABSTRACT

A touch display device, a driving circuit, and a driving method are provided. An image defect which occurs when display driving and touch driving are simultaneously executed can be reduced by performing control such that a voltage level of a touch electrode driving signal (TDS) varies in a section other than a high-level period (Pon) of an ON-clock signal (ON_CLK) and/or a high-level period (Poff) of an OFF-clock signal (OFF_CLK).

CROSS REFERENCE TO RELATED APPLICATION

This application claims priority from the Republic of Korea PatentApplication No. 10-2018-0170592, filed on Dec. 27, 2018, and theRepublic of Korea Patent Application No. 10-2019-0062755, filed on May28, 2019, each of which is hereby incorporated by reference in itsentirety.

BACKGROUND Field of Technology

Embodiments of the present disclosure relate to a touch display device,a driving circuit, and a driving method.

Discussion of the Related Art

With advancement in information-oriented societies, requirements fortouch display devices displaying an image have increased in varioustypes, and various display devices such as a liquid crystal displaydevice and an organic light emitting display device have been widelyutilized in recent years.

Among such display devices, there is a touch display device thatprovides a touch-based input system enabling a user to easily,intuitively, and conveniently input information or commands instead ofnormal input systems using buttons, a keyboard, a mouse, and the like.

In a touch display device according to the related art, since both animage display function and a touch sensing function must be provided,display driving for displaying an image and touch driving for sensing atouch are alternately performed at divided time intervals.

In such a time-division driving system, considerably elaborate timingcontrol is required for accurately performing display driving and touchdriving at divided times in a time-division manner, and expensiveelectronic components may be required.

In the time-division driving system, both a display driving time and atouch driving time may be insufficient and thus there is a problem inthat image quality and touch sensitivity decrease. Particularly, theremay be a problem in that image quality with a high resolution is notprovided due to time-division driving.

Simultaneous execution of display driving and touch has been studied,but there is considerable technical difficulty in simultaneouslyexecuting display driving and touch driving.

In order to simultaneously execute display driving and touch driving,display driving and touch driving have to be stably and accuratelyexecuted, display driving should not interfere with touch driving, andtouch driving should not interfere with display driving.

However, there are problems with occurrence of an image defect and thelike because touch driving is affected by display driving or displaydriving is affected by touch driving. Particularly, such problems becomesevere when touch sensors (touch electrodes) are embedded in a displaypanel and are not easily solvable.

SUMMARY

An objective of embodiments of the disclosure is to provide a touchdisplay device, a driving circuit, and a driving method that cansimultaneously stably execute display driving and touch driving.

Another objective of embodiments of the disclosure is to provide a touchdisplay device, a driving circuit, and a driving method that cansimultaneously stably execute display driving and touch driving using adisplay panel having touch sensors embedded therein.

Another objective of embodiments of the disclosure is to provide a touchdisplay device, a driving circuit, and a driving method that can reducean image defect of a line shape which may be caused by timing mismatchbetween a gate driving relevant signal and a touch electrode drivingsignal.

According to an aspect of the disclosure, there is provided a touchdisplay device including: a display panel in which a plurality of datalines and a plurality of gate lines are arranged, a plurality ofsubpixels are arranged, and a plurality of touch electrodes arearranged; a display controller that outputs an ON-clock signal and anOFF-clock signal; a gate driving circuit that outputs a scan signal tothe plurality of gate lines on the basis of the ON-clock signal and theOFF-clock signal; a data driving circuit that outputs a data signal fordisplaying an image to the plurality of data lines; and a touch drivingcircuit that supplies a touch electrode driving signal, a voltage levelof which varies in a section other than a high-level period of theON-clock signal or a high-level period of the OFF-clock signal, to oneor more of the plurality of touch electrodes, senses one or more of theplurality of touch electrodes, and outputs sensing data.

The touch display device may further include a touch controller thatdetects whether there is a touch or a touch coordinate on the basis ofthe sensing data.

The touch controller may perform control such that the voltage level ofthe touch electrode driving signal varies in a section other than thehigh-level period of the ON-clock signal or the high-level period of theOFF-clock signal.

A frequency of the ON-clock signal and the OFF-clock signal may be N or1/N times a frequency of the touch electrode driving signal (where N isa natural number).

The touch electrode driving signal may have a constant duty ratio.

A frequency of the ON-clock signal and the OFF-clock signal may be otherthan N or 1/N times a frequency of the touch electrode driving signal(where N is a natural number).

The touch electrode driving signal may have a variable duty ratio.

The touch electrode driving signal may include a first signal sectionhaving a first duty ratio and a second signal section having a secondduty ratio which is different from the first duty ratio. Since thesecond signal section of the touch electrode driving signal has thesecond duty ratio which is different from the first duty ratio, thevoltage level in the second signal section of the touch electrodedriving signal can vary in a section other than the high-level period ofthe ON-clock signal and the high-level period of the OFF-clock signal.

The voltage level of the touch electrode driving signal may vary in asection other than a rising section or a falling section of the scansignal.

The touch driving circuit may sense at least one of the plurality oftouch electrodes when display driving is being executed by supplying thedata signal for displaying an image to the plurality of data lines.

The touch electrode driving signal may be a signal of which a voltagelevel varies periodically, and a period or a width of a high-levelvoltage period of the touch electrode driving signal may be longer thanone horizontal time for display driving.

In this case, in the period of the high-level voltage period of thetouch electrode driving signal, a voltage level of the data signal fordisplaying an image which is supplied to at least one data line of theplurality of data lines may vary one or more times, or a voltage levelof the scan signal which is supplied to at least one gate line of theplurality of gate lines may vary one or more times.

The touch electrode driving signal may be a signal of which a voltagelevel varies periodically, and a period or a width of a high-levelvoltage period of the touch electrode driving signal may be shorter thanone horizontal time for display driving.

In this case, in the one horizontal time for display driving, thevoltage level of the touch electrode driving signal may vary one or moretimes.

The data driving circuit may convert an image digital signal into animage analog signal in response to a gamma reference voltage and outputthe data signal corresponding to the image analog signal to the datalines, and a frequency and a phase of the gamma reference voltage maycorrespond to those of the touch electrode driving signal.

The high-level period of the ON-clock signal and the high-level periodof the OFF-clock signal may correspond to each other.

A low-level period of the ON-clock signal and a low-level period of theOFF-clock signal may correspond to each other.

A falling section of a first scan signal which is supplied to a firstgate line of the plurality of gate lines may correspond to a risingsection of another scan signal which is supplied to a gate line otherthan the first gate line out of the plurality of gate lines.

The first gate line and the other gate line may overlap the same touchelectrode.

The other gate line may be a gate line adjacent to the first gate line.On the other hand, one or more gate lines may be disposed between thefirst gate line and the other gate line.

According to another aspect of the disclosure, there is provided a touchdisplay device including: a display panel in which a plurality of datalines and a plurality of gate lines are arranged, a plurality ofsubpixels are arranged, and a plurality of touch electrodes arearranged; a gate driving circuit that sequentially outputs a scan signalto the plurality of gate lines; a data driving circuit that outputs adata signal to the plurality of data lines; and a touch driving circuitthat supplies a touch electrode driving signal, a voltage level of whichvaries in a section other than a rising section or a falling section ofthe scan signal, to one or more of the plurality of touch electrodes.

A falling section of a first scan signal which is supplied to a firstgate line of the plurality of gate lines may correspond to a risingsection of another scan signal which is supplied to a gate line otherthan the first gate line out of the plurality of gate lines.

The first gate line and the other gate line may overlap the same touchelectrode.

According to another aspect of the disclosure, there is provided adriving circuit including: a data driving circuit that outputs a datasignal to data lines which are arranged on a display panel; and a touchdriving circuit that drives one or more of a plurality of touchelectrodes which are arranged on the display panel and outputs a touchelectrode driving signal, a voltage level of which varies in a sectionother than a rising section or a falling section of a scan signal whichis output to gate lines arranged on the display panel, to one or more ofthe plurality of touch electrodes.

The data driving circuit may convert an image digital signal into animage analog signal in response to a gamma reference voltage which ismodulated in synchronization with the touch electrode driving signal andoutput the data signal corresponding to the image analog signal to thedata lines.

A frequency and a phase of the gamma reference voltage may correspond tothose of the touch electrode driving signal.

A falling section of a first scan signal which is supplied to a firstgate line of the plurality of gate lines may correspond to a risingsection of another scan signal which is supplied to a gate line otherthan the first gate line out of the plurality of gate lines.

The first gate line and the other gate line may overlap the same touchelectrode.

According to another aspect of the disclosure, there is provided adriving method of a touch display device, including: a step ofrespectively outputting a data signal and a scan signal to data linesand gate lines which are arranged on a display panel and outputting atouch electrode driving signal to one or more of a plurality of touchelectrodes which are arranged on the display panel; and a step ofdisplaying an image in response to the data signal and the touchelectrode driving signal and sensing a touch on the basis of a result ofsensing of the touch electrodes to which the touch electrode drivingsignal is supplied.

A voltage level of the touch electrode driving signal may vary in asection other than a rising section or a falling section of a scansignal.

A falling section of a first scan signal which is supplied to a firstgate line of the plurality of gate lines may correspond to a risingsection of another scan signal which is supplied to a gate line otherthan the first gate line out of the plurality of gate lines.

The first gate line and the other gate line may overlap the same touchelectrode.

According to embodiments of the disclosure, it is possible to provide atouch display device, a driving circuit, and a driving method that cansimultaneously stably execute display driving and touch driving.

According to embodiments of the disclosure, it is possible to provide atouch display device, a driving circuit, and a driving method that cansimultaneously stably execute display driving and touch driving using adisplay panel having touch sensors embedded therein.

According to embodiments of the disclosure, it is possible to provide atouch display device, a driving circuit, and a driving method that canreduce an image defect of a line shape which may be caused by timingmismatch between a gate driving relevant signal and a touch electrodedriving signal.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram schematically illustrating a system configuration ofa touch display device according to one embodiment;

FIG. 2 is a diagram schematically illustrating display driving of thetouch display device according to one embodiment;

FIG. 3 is a diagram schematically illustrating touch driving of thetouch display device according to one embodiment;

FIGS. 4 and 5 are diagrams illustrating a time-division driving systemof the touch display device according to one embodiment;

FIG. 6 is a diagram illustrating a time-free driving system of the touchdisplay device according to one embodiment;

FIG. 7 is a diagram illustrating three cases of time-free driving in thetouch display device according to one embodiment;

FIG. 8 is a diagram illustrating various timings for finger sensing andpen sensing based on a time-free driving system in the touch displaydevice according to one embodiment;

FIG. 9 is a diagram illustrating touch electrode driving signals TDS inthree cases of time-free driving in the touch display device accordingto one embodiment;

FIG. 10 is a diagram illustrating waveforms of principal signals inthree cases of time-free driving in the touch display device accordingto one embodiment;

FIG. 11 is a diagram illustrating a time-free driving system in thetouch display device according to one embodiment;

FIG. 12 is a diagram illustrating a signal transmission system betweenelements for Case 1 of three cases of time-free driving in the touchdisplay device according to one embodiment;

FIG. 13 is a diagram illustrating a signal transmission system betweenelements for Case 2 of three cases of time-free driving in the touchdisplay device according to one embodiment;

FIG. 14 is a diagram illustrating a signal transmission system betweenelements for Case 3 of three cases of time-free driving in the touchdisplay device according to one embodiment;

FIG. 15 is a diagram illustrating an example of a gamma block forperforming time-free driving on data lines using a gamma modulationmethod in the time-free driving system of the touch display deviceaccording to one embodiment;

FIG. 16 is a diagram illustrating voltage levels and characteristics ofgamma reference voltages which are used in a gamma block for performingtime-free driving on data lines using a gamma modulation method in thetime-free driving system of the touch display device according to oneembodiment;

FIG. 17 is a diagram illustrating waveforms of principal signals fortime-free driving when a frequency of a touch electrode driving signalis high in the touch display device according to one embodiment;

FIG. 18 is a diagram illustrating waveforms of principal signals fortime-free driving when a frequency of a touch electrode driving signalis low in the touch display device according to one embodiment;

FIG. 19 is a diagram illustrating a process of generating a scan signalfor gate driving in the touch display device according to oneembodiment;

FIG. 20 is a diagram illustrating an ON-clock signal, an OFF-clocksignal, and a scan signal which are associated with gate driving in thetouch display device according to one embodiment;

FIGS. 21 and 22 are diagrams illustrating a case in which a voltagelevel of a touch electrode driving signal varies in a high-level sectionof an OFF-clock signal and an image defect of a line pattern basedthereon in the touch display device according to one embodiment;

FIGS. 23A and 23B are diagrams illustrating a driving method forreducing an image defect of a line pattern from occurring due to timingmismatch between a gate driving relevant signal and a touch electrodedriving signal in the touch display device according to one embodiment;

FIG. 24 is a diagram illustrating control for allowing a voltage levelof a touch electrode driving signal to vary in a period other than ahigh-level period of an OFF-clock signal when a frequency of a touchelectrode driving signal and a frequency of an ON-clock signal and anOFF-clock signal are different from each other in the touch displaydevice according to one embodiment;

FIGS. 25A and 25B are diagrams illustrating control for allowing avoltage level of a touch electrode driving signal to vary in a periodother than a high-level period of an OFF-clock signal when a frequencyof an OFF-clock signal doubles a frequency of a touch electrode drivingsignal in the touch display device according to one embodiment;

FIGS. 26A and 26B are diagrams illustrating control for allowing avoltage level of a touch electrode driving signal to vary in a periodother than a high-level period of an OFF-clock signal when a frequencyof an OFF-clock signal quadruples a frequency of a touch electrodedriving signal in the touch display device according to one embodiment;

FIGS. 27 and 28 are diagrams illustrating effects of gate drivingcontrol in the touch display device according to one embodiment; and

FIG. 29 is a flowchart illustrating a driving method of the touchdisplay device according to one embodiment.

DETAILED DESCRIPTION

Advantages and features of the disclosure and methods for achieving theadvantages or features will be apparent from embodiments described belowin detail with reference to the accompanying drawings. However, thedisclosure is not limited to the embodiments but can be modified invarious forms. The embodiments are provided merely for completing thedisclosure of the invention and are provided for completely informingthose skilled in the art of the scope of the disclosure. The scope ofthe invention is defined by only the appended claims.

Shapes, sizes, ratios, angles, number of pieces, and the likeillustrated in the drawings, which are provided for explaining theembodiments of the disclosure, are exemplary and thus the disclosure isnot limited to the illustrated details. In the following description,like elements are referenced by like reference numerals. When it isdetermined that detailed description of the relevant known functions orconfigurations involved in the disclosure makes the gist of thedisclosure obscure, the detailed description thereof will not be made.When “include,” “have”, “be constituted”, and the like are mentioned inthe specification, another element may be added unless “only” is used. Asingular expression of an element includes two or more elements unlessdifferently mentioned.

In construing elements in embodiments of the disclosure, an error rangeis included even when explicit description is not made.

Terms such as “first”, “second”, “A”, “B”, “(a)”, and “(b)” can be usedto describe elements of the disclosure. These terms are merely used todistinguish one element from another element and the essence, order,sequence, number, or the like of the elements is not limited to theterms. If it is mentioned that an element is “linked,” “coupled,” or“connected” to another element, it should be understood that the elementcan be directly coupled or connected to another element or still anotherelement may be “interposed” therebetween or the elements may be“linked,” “coupled,” or “connected” to each other with still anotherelement interposed therebetween. For example, when positionalrelationships between two parts are described using ‘on-’, ‘over-’,‘under-’, ‘next-’, and the like, one or more other parts may be disposedbetween the two parts unless ‘just’ or ‘direct’ is used.

Terms such as “first”, “second”, and the like can be used to describevarious elements, but the elements should not be limited to the terms.The terms are used only to distinguish an element from another.Therefore, a first element may be a second element within the technicalspirit of the disclosure.

Features (elements) of embodiments of the disclosure can be coupled orcombined with each other or separated from each other partially or onthe whole and can be technically interlinked and driven in variousforms. The embodiments may be put into practice independently or incombination.

Hereinafter, embodiments of the disclosure will be described in detailwith reference to the accompanying drawings.

FIG. 1 is a diagram schematically illustrating a system configuration ofa touch display device according to one embodiment. FIG. 2 is a diagramschematically illustrating display driving of the touch display deviceaccording to one embodiment. FIG. 3 is a diagram schematicallyillustrating touch driving of the touch display device according to oneembodiment.

Referring to FIG. 1, a touch display device can provide a displayfunction of displaying an image. The touch display device can alsoprovide a touch sensing function of sensing a user's touch and a touchinput function of performing an input process based on a user's touchusing the touch sensing result.

In the following description, elements for providing a display functionand display driving will be described with reference to FIGS. 1 and 2,and elements for providing a touch sensing function and touch drivingwill be described with reference to FIGS. 1 and 3.

Referring to FIGS. 1 and 2, the touch display device includes a displaypanel DISP in which a plurality of data lines DL and a plurality of gatelines GL are arranged and a plurality of subpixels SP defined by theplurality of data lines DL and the plurality of gate lines GL arearranged, a data driving circuit DDC that drives the plurality of datalines DL, a gate driving circuit GDC that drives the plurality of gatelines GL, and a display controller DCTR that controls the data drivingcircuit DDC and the gate driving circuit GDC.

The display controller DCTR supplies various control signals to the datadriving circuit DDC and the gate driving circuit GDC and controls thedata driving circuit DDC and the gate driving circuit GDC.

The display controller DCTR starts scanning at timings which arerealized in each frame, converts input image data which is input fromthe outside to correspond to a data signal format which is used in thedata driving circuit DDC, outputs the converted image data, and controlsdata driving at appropriate timings to correspond to the scanning.

The gate driving circuit GDC sequentially supplies a gate signal of anON voltage or an OFF voltage to the plurality of gate lines GL under thecontrol of the display controller DCTR.

When a specific gate line GL is selected by the gate driving circuitGDC, the data driving circuit DDC converts an image data signal which isreceived from the display controller DCTR into an image analog signaland supplies a data signal Vdata corresponding thereto to the pluralityof data lines DL.

The display controller DCTR may be a timing controller which is used fornormal display techniques or a control device that performs anothercontrol function in addition to the timing controller or may be acontrol device that is different from the timing controller.

The display controller DCTR may be embodied as a component separatedfrom the data driving circuit DDC or may be embodied as an integratedcircuit along with the data driving circuit DDC.

The data driving circuit DDC drives the plurality of data lines DL bysupplying a data signal Vdata to the plurality of data lines DL. Here,the data driving circuit DDC is also referred to as a “source driver”.

The data driving circuit DDC may include at least one source driverintegrated circuit SDIC. Each source driver integrated circuit SDIC mayinclude a shift register, a latch circuit, a digital-to-analog converterDAC, and an output buffer circuit. Each source driver integrated circuitSDIC may further include an analog-to-digital converter ADC in somecases.

Each source driver integrated circuit SDIC may be connected to a bondingpad of the display panel DISP in a tape automated bonding (TAB) systemor a chip-on-glass (COG) system, may be disposed directly on the displaypanel DISP, or may be integrated and disposed on the display panel DISPin some cases. Each gate driver integrated circuit GDIC may be realizedin a chip-on-film (COF) system in which it is mounted on a filmconnected to the display panel DISP.

The gate driving circuit GDC sequentially drives the plurality of gatelines GL by sequentially supplying a scan signal Vgate (which is alsoreferred to as a scan voltage, a scan signal, or a gate voltage) to theplurality of gate lines GL. Here, the gate driving circuit GDC is alsoreferred to as a “scan driver.”

Here, the scan signal Vgate is constituted by an OFF-level gate voltagefor closing the corresponding gate line GL and an ON-level gate voltagefor opening the corresponding gate line GL.

More specifically, the scan signal Vgate is constituted by an OFF-levelgate voltage for turning off transistors connected to the correspondinggate line GL and an ON-level gate voltage for turning on the transistorsconnected to the corresponding gate line GL.

When the transistors are of an N type, the OFF-level gate voltage may bea low-level gate voltage VGL_M and the ON-level gate voltage may be ahigh-level gate voltage VGH_M. When the transistors are of a P type, theOFF-level gate voltage may be a high-level gate voltage VGH_M and theON-level gate voltage may be a low-level gate voltage VGL_M. In thefollowing description, for the purpose of convenience of explanation, itis assumed that the OFF-level gate voltage is a low-level gate voltageVGL_M and the ON-level gate voltage is a high-level gate voltage VGH_M.

The gate driving circuit GDC may include at least one gate driverintegrated circuit GDIC. Each gate driver integrated circuit GDIC mayinclude a shift register and a level shifter.

Each gate driver integrated circuit GDIC may be connected to a bondingpad of the display panel DISP in a tape automated bonding (TAB) systemor a chip on glass (COG) system or may be realized in a gate in panel(GIP) system and disposed directly on the display panel DISP. In somecases, each gate driver integrated circuit GDIC may be integrated anddisposed on the display panel DISP. Each gate driver integrated circuitGDIC may be realized in a chip on film (COF) system in which it ismounted on a film connected to the display panel DISP.

The data driving circuit DDC may be disposed on only one side (forexample, an upper side or a lower side) of the display panel DISP asillustrated in FIG. 1 or may be disposed on both sides (in other words,two opposite sides; for example, the upper side and the lower side) ofthe display panel DISP depending on a driving system, a panel designsystem, or the like in some cases.

The gate driving circuit GDC may be disposed on only one side (forexample, a right side or a left side) of the display panel DISP asillustrated in FIG. 1 or may be disposed on both sides (in other words,two opposite sides; for example, the right side and the left side) ofthe display panel DISP depending on a driving system, a panel designsystem, or the like in some cases.

The touch display device may be various types of display devices such asa liquid crystal display device and an organic light-emitting displaydevice. The display panel DISP may be various types of display panelssuch as a liquid crystal display panel and an organic light-emittingdisplay panel.

Each subpixel SP arranged in the display panel DISP may include one ormore circuit elements (for example, a transistor and a capacitor).

For example, when the display panel DISP is a liquid crystal displaypanel, a pixel electrode is disposed in each subpixel SP and atransistor is electrically connected between the pixel electrode and thecorresponding data line DL. The transistor can be turned on by a scansignal Vgate which is supplied to a gate node via the corresponding gateline GL, and can output a data signal Vdata which is supplied to asource node (or a drain node) via the corresponding data line DL to thedrain node (or the source node) and apply the data signal Vdata to thepixel electrode electrically connected to the drain node (or the sourcenode) when it is turned on. An electric field is formed between thepixel electrode to which the data signal Vdata is applied and a commonelectrode to which a common voltage Vcom is applied, and a capacitor canbe formed between the pixel electrode and the common electrode.

The structure of each subpixel SP can be determined variously dependingon a panel type, a provided function, a design system, and the like.

Referring to FIGS. 1 and 3, the touch display device may include a touchpanel TSP, a touch driving circuit TDC that drives the touch panel TSPand performs sensing, and a touch controller TCTR that senses a touchusing the sensing result of the touch panel TSP from the touch drivingcircuit TDC to provide a touch sensing function.

The display panel DISP can be touched or approached by a user's pointer.Touch sensors may be disposed on the touch panel TSP.

Here, a user's pointer may be a finger or a pen.

The pen may be a passive pen not having a signal transmitting/receivingfunction or an active pen having a signal transmitting/receivingfunction. The touch driving circuit TDC can supply a touch drivingsignal to the touch panel TSP and sense the touch panel TSP. The touchcontroller TCTR may sense a touch using the sensing result of the touchpanel TSP from the touch driving circuit TDC. Here, “senses a touch”means that whether a touch has been made and/or a touch coordinate isdetermined.

The touch panel TSP may be an outer-mounted type in which it is disposedoutside the display panel DISP or an embedded type in which it isdisposed inside the display panel DISP.

When the touch panel TSP is an outer-mounted type, the touch panel TSPand the display panel DISP may be separately manufactured and then becoupled to each other by an adhesive or the like. The outer-mountedtouch panel TSP is also referred to as an Add-on type.

When the touch panel TSP is an embedded type, the touch panel TSP can bemanufactured together in the process of manufacturing the display panelDISP. That is, touch sensors constituting the touch panel TSP can bedisposed in the display panel DISP. The embedded type touch panel TSPmay be an In-cell type, an On-cell type, a hybrid type, or the like.

On the other hand, for the purpose of convenience of explanation, it isassumed in the following description that the touch panel TSP is anembedded type in which it is disposed inside the display panel DISP.

When the touch panel TSP is embedded in the display panel DISP, that is,when a plurality of touch electrodes TE are arranged in the displaypanel DISP, the plurality of touch electrodes TE may be disposed in thedisplay panel DISP separately from electrodes which are used for displaydriving or the electrodes which are disposed in the display panel DISPfor display driving may be used as the plurality of touch electrodes TE.

For example, the common electrode disposed in the display panel DISP maybe divided into a plurality of parts and may be used as the plurality oftouch electrodes TE. That is, the plurality of touch electrodes TEdisposed in the display panel DISP may be electrodes for touch sensingand may be electrodes for display driving. In the following description,it is assumed that the plurality of touch electrodes TE disposed in thedisplay panel DISP are common electrodes.

The touch controller TCTR may be realized, for example, by a microcontrol unit MCU or a processor.

The display controller DCTR and the touch controller TCTR may beseparately embodied or may be integrally embodied.

Referring to FIG. 3, a plurality of touch electrodes TE are arranged inthe touch panel TSP of the touch display device and a plurality of touchlines TL that electrically connect the plurality of touch electrodes TEto the touch driving circuit TDC are disposed therein. One or more touchlines TL can be electrically connected to each touch electrode TE viaone or more contact holes.

The touch display device can sense a touch based on self-capacitance ofthe touch electrodes TE or sense a touch based on mutual-capacitancebetween the touch electrodes TE.

When the touch display device senses a touch based onmutual-capacitance, a plurality of first touch electrode lines and aplurality of second touch electrode lines can be arranged to cross eachother. For example, the plurality of first touch electrode lines can bearranged in an X-axis direction and the plurality of second touchelectrode lines can be arranged in a Y-axis direction. Here, each of thefirst touch electrode line and the second touch electrode line may be asingle touch electrode with a bar shape or may have a shape in which twoor more touch electrodes are electrically connected to each other. Thefirst touch electrode lines can be referred to as driving lines, drivingelectrodes, driving touch electrode lines, Tx lines, Tx electrodes, orTx touch electrode lines. The second touch electrode lines can bereferred to as receiving lines, receiving electrodes, receiving touchelectrode lines, sensing lines, sensing electrodes, sensing touchelectrode lines, Rx lines, Rx electrodes, or Rx touch electrode lines.

In this case, the touch driving circuit TDC can supply a driving signalto one or more of the plurality of first touch electrode lines, sensethe second touch electrode lines, and output sensing data. The touchcontroller TCTR can calculate whether there is a touch and/or a touchcoordinate using the sensing data.

When the touch display device senses a touch based on self-capacitance,a plurality of touch electrodes TE can be separately arranged in thetouch panel TSP as illustrated in FIG. 3.

In this case, the touch driving circuit TDC can supply a driving signal(hereinafter referred to as a touch electrode driving signal TDS) to allor some of the plurality of touch electrodes TE, sense one or more touchelectrodes TE to which the driving signal has been supplied, and outputsensing data. The touch controller TCTR can calculate whether there is atouch and/or a touch coordinate using the sensing data.

In the following description, for the purpose of convenience ofexplanation, it is assumed that the touch display device senses a touchbased on self-capacitance and that the touch panel TSP is configured asillustrated in FIGS. 2 and 3.

A touch electrode driving signal TDS which is output from the touchdriving circuit TDC may be a signal of a constant voltage or may be asignal of a variable voltage.

When the touch electrode driving signal TDS is a signal of a variablevoltage, the touch electrode driving signal TDS may have various signalwaveforms such as a sinusoidal waveform, a triangular waveform, or arectangular waveform.

In the following description, it is assumed that, when the touchelectrode driving signal TDS is a signal of a variable voltage, thetouch electrode driving signal TDS is a pulse signal including two ormore pulses. When the touch electrode driving signal TDS is a pulsesignal including two or more pulses, the touch electrode driving signalTDS may have a constant frequency or may have a variable frequency.

Referring to FIGS. 2 and 3, the size of an area which is occupied by onetouch electrode TE may correspond to the size of an area which isoccupied by one subpixel SP or may correspond to the size of an areawhich is occupied by two or more subpixels SP. That is, each of theplurality of touch electrodes TE may overlap two or more subpixels SP.

When it is assumed that a plurality of touch electrodes TE are arrangedin a matrix and a first touch electrode and a second touch electrode ofthe plurality of touch electrodes TE are disposed in the same column (orthe same row), two or more data lines DL overlapping the first touchelectrode may overlap the second touch electrode. Two or more gate linesGL overlapping the first touch electrode do not overlap the second touchelectrode.

A plurality of touch electrode columns (or touch electrode rows) may bedisposed to be parallel to a plurality of data lines DL. A plurality oftouch lines TL may be disposed to be parallel to a plurality of datalines DL.

A plurality of touch electrodes TE are arranged in one touch electrodecolumn (or touch electrode row), and a plurality of touch lines TLelectrically connected to a plurality of touch electrodes TE may overlapa plurality of touch electrodes TE.

For example, when it is assumed that a plurality of touch electrodes TEarranged in one touch electrode column includes a first touch electrodeand a second touch electrode, a first touch line electrically connectsthe first touch electrode to the touch driving circuit TDC, and a secondtouch line electrically connects the second touch electrode to the touchdriving circuit TDC, the first touch line connected to the first touchelectrode can overlap the second touch electrode (the touch electrodedisposed in the same column as the first touch electrode) but beelectrically isolated from the second touch electrode in the displaypanel DISP. On the other hand, the first touch line and the second touchline may be short-circuited depending on a driving situation or ifnecessary in the touch driving circuit TDC.

FIGS. 4 and 5 are diagrams illustrating a time-division driving (TDD)system of the touch display device according to one embodiment.

Referring to FIG. 4, the touch display device can alternately performdisplay and touch sensing. In this way, a system in which displaydriving for display and touch driving for touch sensing are alternatelyperformed is referred to as a time-division driving system.

In the time-division driving system, a display period for display and atouch sensing period for touch sensing alternate. The touch displaydevice can perform display driving in the display period. The touchdisplay device can perform touch driving in the touch sensing period.

In an example of the time-division driving system, one frame time can bedivided into a display period and a touch sensing period. In anotherexample of the time-division driving system, one frame time can bedivided into two or more display periods and one or two or more touchsensing periods.

Referring to FIG. 4, in the time-division driving system, the touchelectrode driving signal TDS can be applied to one or more of theplurality of touch electrodes TE. At this time, the plurality of datalines DL and the plurality of gate lines GL may not be driven.

In this case, unnecessary parasitic capacitance due to a potentialdifference can be formed between a touch electrode TE to which the touchelectrode driving signal TDS is applied and one or more data lines DLlocated in the vicinity thereof. This unnecessary parasitic capacitancecan increase an RC delay between the corresponding touch electrode TEand the touch line TL connected thereto so that touch sensitivity maydecrease.

In this case, unnecessary parasitic capacitance due to a potentialdifference can be formed between a touch electrode TE to which the touchelectrode driving signal TDS is applied and one or more gate lines GLlocated in the vicinity thereof. This unnecessary parasitic capacitancecan increase an RC delay between the corresponding touch electrode TEand the touch line TL connected thereto so that touch sensitivity maydecrease.

In this case, unnecessary parasitic capacitance due to a potentialdifference can be formed between a touch electrode TE to which the touchelectrode driving signal TDS is applied and one or more other touchelectrodes TE located in the vicinity thereof. This unnecessaryparasitic capacitance can increase an RC delay between the correspondingtouch electrode TE and the touch line TL connected thereto so that touchsensitivity may decrease.

The above-mentioned RC delay is referred to as a time constant or aload.

To remove the load, the touch display device can perform load-freedriving LFD in the touch sensing period.

Referring to FIG. 5, in the touch display device, when the touchelectrode driving signal TDS is applied to all or some of the pluralityof touch electrodes TE at the time of load-free driving, a load-freedriving signal can be applied as a data signal Vdata to all the datalines DL or some data lines DL for which there is a likelihood thatparasitic capacitance will be formed.

Referring to FIG. 5, in the touch display device, when the touchelectrode driving signal TDS is applied to all or some of the pluralityof touch electrodes TE at the time of load-free driving, a load-freedriving signal can be applied as a gate signal Vgate to all the gatelines GL or some gate lines GL for which there is a likelihood thatparasitic capacitance will be formed.

In the touch display device, when the touch electrode driving signal TDSis applied to some of the plurality of touch electrodes TE at the timeof load-free driving, a load-free driving signal can be applied to allthe touch electrodes or some other touch electrodes TE for which thereis a likelihood that parasitic capacitance will be formed (not shown inFIG. 5).

The load-free driving signal may be a touch electrode driving signal ormay be a signal having signal characteristics equal or similar to thoseof the touch electrode driving signal. For example, the frequency andthe phase of the load-free driving signal may be completely equal to thefrequency and the phase of the touch electrode driving signal TDS or maybe equal thereto within a predetermined error range. The amplitude ofthe load-free driving signal and the amplitude of the touch electrodedriving signal TDS may be completely equal or may be equal within apredetermined error range, and may have an intentional difference insome cases.

FIG. 6 is a diagram illustrating a time-free driving (TFD) system of thetouch display device according to one embodiment.

Referring to FIG. 6, the touch display device can independently performdisplay and touch sensing. In this way, a driving system in whichdisplay driving for display and touch driving for touch sensing areindependently performed is referred to as a time-free driving system.

In the time-free driving system, display driving for display and touchdriving for touch sensing may be simultaneously performed. In a certainperiod, only display driving for display can be performed or only touchdriving for touch sensing can be performed.

FIG. 7 is a diagram illustrating three cases (Cases 1, 2, and 3) oftime-free driving when the touch display device performs time-freedriving according to one embodiment. FIG. 8 is a diagram illustratingvarious timings for finger sensing (F/S) and pen sensing (P/S) based onthe time-free driving system in the touch display device according toone embodiment. FIG. 9 is a diagram illustrating touch electrode drivingsignals TDS in three cases (Cases 1, 2, and 3) of the time-free drivingin the touch display device according to one embodiment.

In Case 1 of time-free driving, the touch display device cansimultaneously perform display driving and touch driving. In this case,while display driving is being performed by supplying a data signalVdata for displaying an image to a plurality of data lines DL from thedata driving circuit DDC, the touch driving circuit TDC can sense atleast one of a plurality of touch electrodes TE

In Case 1, the touch display device can supply a touch electrode drivingsignal TDS of a variable voltage to the touch electrodes TE to performtouch driving.

In the following description, the touch electrode driving signal TDSwhich is applied to the touch electrodes TE in Case 1 is referred to asa first touch electrode driving signal TDS1. The first touch electrodedriving signal TDS1 has a first amplitude AMP1.

In Case 1, the touch display device can perform touch driving and sensea touch of a finger with the touch panel TSP. This touch sensing isreferred to as finger sensing.

Alternatively, in Case 1, the touch display device can perform touchdriving and sense a touch of a finger or a pen when the finger or thepen does not touch the touch panel TSP but approaches the touch panelTSP. This touch sensing is referred to as hover sensing.

In Case 2 of time-free driving, the touch display device can performonly display driving.

In Case 2, since the touch display device does not need to sense a touchof a finger, the touch display device does not perform general touchdriving. That is, the touch display device does not supply the touchelectrode driving signal TDS of a variable voltage to the plurality oftouch electrodes TE which are disposed in the touch panel TSP.

In Case 2, the touch display device can supply the touch electrodedriving signal TDS of a DC voltage. In the following description, thetouch electrode driving signal TDS which is applied to the touchelectrodes TE in Case 2 is referred to as a second touch electrodedriving signal TDS2.

On the other hand, in Case 2, the touch display device can receive a pensignal output from a pen and sense the pen. The touch display device canacquire a result of pen sensing, a position, a tilt, and a pressure (apen pressure) of a pen, or various additional information.

In Case 3 of time-free driving, the touch display device can performonly touch driving.

In Case 3, the touch display device can supply a touch electrode drivingsignal TDS of a variable voltage to the touch electrodes TE for thepurpose of touch driving.

In the following description, the touch electrode driving signal TDSwhich is applied to the touch electrodes TE in Case 3 is referred to asa third touch electrode driving signal TDS3. The third touch electrodedriving signal TDS3 has a third amplitude AMPS which is different fromthe first amplitude AMP1.

In Case 3, the touch display device can sense a touch of a finger withthe touch panel TSP by performing touch driving.

Referring to FIG. 7, among three cases (Cases 1, 2, and 3) of time-freedriving in the touch display device, Case 1 can be carried out in anactive time and Case 3 can be carried out in a blank time. Here, anactive time corresponds to a time in which a screen of one frame isdisplayed and a blank time corresponds to a time required until a screenof a next frame is displayed after a screen of one frame has beendisplayed.

Referring to FIG. 7, Case 1 can be switched to Case 2 in the activetime.

Referring to FIG. 7, in the active time, the touch display device canstop touch driving for finger sensing while simultaneously carrying outdisplay driving and touch driving (Case 1 is carried out) (that is, Case1 is switched to Case 2).

In Cases 1 and 3, touch electrode driving signals TDS1 and TDS3 havingamplitudes AMP1 and AMP3 can be applied to the touch electrodes TE atthe time of touch driving for finger sensing.

In Case 2, a touch electrode driving signal TDS2 of a DC voltage can beapplied to the touch electrodes TE for the purpose of pen sensing.

On the other hand, referring to FIG. 9, the first amplitude AMP1 of thefirst touch electrode driving signal TDS1 which is applied to the touchelectrodes TE when display driving and touch driving are simultaneouslyperformed (Case 1) can be less than the third amplitude AMP3 of thethird touch electrode driving signal TDS3 which is applied to the touchelectrodes TE when only touch driving is performed (Case 3).

The first amplitude AMP1 of the first touch electrode driving signalTDS1 which is applied to the touch electrodes TE in the active time canbe less than the third amplitude AMP3 of the third touch electrodedriving signal TDS3 which is applied to the touch electrodes TE in theblank time.

Referring to FIGS. 7 and 9, in the active time, the touch drivingcircuit TDC can supply the first touch electrode driving signal TDS1having the first amplitude AMP1 or the second touch electrode drivingsignal TDS2 having a DC voltage to the plurality of touch electrodes TE.

Referring to FIGS. 7 and 9, in the blank time, the touch driving circuitTDC can supply the third touch electrode driving signal TDS3 having thethird amplitude AMP3 to one or more of the plurality of touch electrodesTE.

On the other hand, driving corresponding to Case 1 may be performed inone frame or may be performed in only a partial time interval of oneframe. Driving corresponding to Case 2 may be performed in all frames orsome frames or may be performed in only a partial time interval of oneframe. At the time of driving corresponding to Case 3, driving forfinger sensing may be performed or driving for pen sensing may beperformed.

Referring to FIG. 8, in the time-free driving system of the touchdisplay device, finger sensing F/S and pen sensing P/S can be performedat various timings.

For example, as in the i-th frame, only display driving for display maybe performed without performing finger sensing F/S and pen sensing P/Sin one frame. This corresponds to Case 2 in which pen sensing P/S is notperformed.

As in the j-th frame, finger sensing F/S may be performed in only apartial time interval necessary in one frame time. This corresponds toCase 1. Pen sensing P/S may be performed in only a partial time intervalnecessary in one frame time. This corresponds to Case 2. In one frame,finger sensing F/S and pen sensing P/S may be performed in partial timeintervals which do not overlap in one frame time.

As in the k-th frame, finger sensing F/S and pen sensing P/S may beperformed in time intervals overlapping in one frame. In this case, thesensing results of finger sensing F/S and pen sensing P/S can bedistinguished by a predetermined algorithm or signal analysis based on asensing position using the touch controller TCTR or the like.

In addition to the above-mentioned examples, display and touch sensing(finger sensing and/or pen sensing) can be independently performed atvarious timings.

FIG. 10 is a diagram illustrating waveforms of principal signals TDS1,Vdata, VGL_M, and VGH_M in three cases (Case 1, Case 2, and Case 3) oftime-free driving in the touch display device according to oneembodiment.

Cases 1 and 2 are cases of driving in an active time. Case 3 is a caseof driving in a blank time.

In the three cases, a touch electrode driving signal TDS is applied tothe touch electrodes TE, a data signal Vdata is supplied to the datalines DL, and an OFF-level gate voltage VGL_M and an ON-level gatevoltage VGH_M are supplied to the gate driving circuit GDC to generate ascan signal which is supplied to the gate lines GL.

In Case 2 in which only display driving is performed in the active time,the touch electrode driving signal TDS which is applied to the touchelectrodes TE is a second touch electrode driving signal TDS2 of a DCvoltage.

The data signal Vdata which is applied to the data lines DL is a signalcorresponding to an image analog signal into which an image digitalsignal is converted in a digital-analog conversion manner for thepurpose of display and may be a pixel voltage which is applied to apixel electrode of the corresponding subpixel SP via the correspondingdata line DL. The data signal Vdata can swing between a drive voltageAVDD, which may be a high-level voltage, and a base voltage AVSS, whichmay be a low-level voltage.

The OFF-level gate voltage VGL_M and the ON-level gate voltage VGH_Mconstituting the scan signal Vgate which is applied to the gate lines GLare DC voltages.

As described above, the touch electrodes TE can also serve as a commonelectrode for display driving. Accordingly, in Case 2 in which onlydisplay driving is performed in the active time, the second touchelectrode driving signal TDS2 which is applied to the touch electrodesTE corresponds to a common voltage for display.

Accordingly, in the corresponding subpixel SP, an electric field isformed between the pixel electrode and the touch electrode TE due to avoltage difference between the data signal Vdata which is applied to thepixel electrode via the data line DL and the second touch electrodedriving signal TDS2 corresponding to the common voltage which is appliedto the touch electrode TE, and thus desired light can be emitted fromthe subpixel SP.

In Case 3 in which only touch driving is performed in the blank time,the touch electrode driving signal TDS which is applied to the touchelectrodes TE is a third touch electrode driving signal TDS3 having thethird amplitude AMPS.

In the blank time, the data lines DL conventionally may be supplied witha data signal corresponding to a DC voltage or may be in a floatingstate. In the blank time, the gate lines GL conventionally may besupplied with a scan signal of an OFF-level gate voltage correspondingto a DC voltage or may be in an electrical floating state.

When load-free driving is performed in the blank time in which onlytouch driving is performed, the data lines DL and the gate lines GL canswing in the same way as the touch electrodes TE from the viewpoint ofvoltage characteristics.

The data signal Vdata which is applied to the data lines DL in the blanktime in accordance with load-free driving may be the third touchelectrode driving signal TDS3 or a load-free driving signal havingsignal characteristics (for example, a phase, a frequency, and anamplitude) equal or similar to those of the third touch electrodedriving signal TDS3.

The OFF-level gate voltage VGL_M which is applied to the gate lines GLin the blank time in accordance with load-free driving may be the thirdtouch electrode driving signal TDS3 or a load-free driving signal havingsignal characteristics (for example, a phase, a frequency, and anamplitude) equal or similar to those of the third touch electrodedriving signal TDS3.

In Case 1 in which display driving and touch driving are simultaneouslyperformed in the active time, the touch electrode driving signal TDSwhich is applied to the touch electrodes TE is a first touch electrodedriving signal TDS1 having the first amplitude AMP1.

In Case 1, since display driving and touch driving are simultaneouslyperformed in the active time, the first touch electrode driving signalTDS1 is a touch driving signal for touch sensing and also serves as adisplay common voltage Vcom for forming capacitance with a data signalVdata.

The first touch electrode driving signal TDS1 which is applied to thetouch electrodes TE should have a predetermined voltage difference fordisplay from the data signal Vdata corresponding to a pixel voltage fordisplay.

In Case 1 in which display driving and touch driving are simultaneouslyperformed, the first touch electrode driving signal TDS1 performs twofunctions (a driving signal for touch sensing and a common voltage fordisplay).

As described above, since the common voltage Vcom corresponding to thefirst touch electrode driving signal TDS1 is not a fixed voltage but avariable voltage, the data signal Vdata which is applied to the datalines DL should be subjected to an additional voltage variation of thefirst amplitude AMP1 of the first touch electrode driving signal TDS1 inaddition to the original voltage variation for display in order toreduce the data lines DL from being affected by touch driving.

Accordingly, in the voltage difference between the data signal Vdatacorresponding to the pixel voltage and the first touch electrode drivingsignal TDS1 corresponding to the common voltage Vcom, a voltagevariation part (that is, the first amplitude AMP1) of the first touchelectrode driving signal TDS1 is excluded and only the original voltagevariation for display is left. Accordingly, normal display can beperformed.

Accordingly, the data signal Vdata in Case 1 in which display drivingand touch driving are simultaneously performed may have a signal patternin which the first touch electrode driving signal TDS1 and the datasignal Vdata in the case (Case 2) in which only display driving isperformed are combined.

In other words, the data signal Vdata in Case 1 in which display drivingand touch driving are simultaneously performed may have a signal patternwhich is obtained by offsetting the original data signal Vdata in thecase (Case 2) in which only display driving is performed using the firsttouch electrode driving signal TDS1. Here, the data signal Vdata may besubjected to a large voltage variation between the drive voltage AVDDand the base voltage AVSS.

Accordingly, the voltage difference between the data signal Vdata andthe first touch electrode driving signal TDS1 in Case 1 in which displaydriving and touch driving are simultaneously performed is the same as avoltage difference between the data signal Vdata and the second touchelectrode driving signal TDS2 in Case 2 in which only display driving isperformed.

In Case 1, since display driving and touch driving are simultaneouslyperformed, load-free driving may be required.

That is, in Case 1, since display driving and touch driving aresimultaneously performed, it may be necessary to reduce parasiticcapacitance from being formed between the touch electrodes TE and thedata lines DL due to touch driving and to reduce parasitic capacitancefrom being formed between the touch electrodes TE and the gate lines GLdue to touch driving.

As described above, in Case 1, since the voltages of the touchelectrodes TE and the data lines DL fluctuate with a voltage variationof the first touch electrode driving signal TDS1, only a voltagedifference for display is present between the touch electrodes TE andthe data lines DL and unnecessary parasitic capacitance due to touchdriving is not formed. That is, in Case 1, load-free driving for thedata lines DL is necessarily performed.

In Case 1, the OFF-level gate voltage VGL_M and the ON-level gatevoltage VGH_M which are supplied to the gate driving circuit GDC suchthat the gate driving circuit GDC can generate a scan signal SCAN whichis applied to the gate lines GL may be load-free driving signals havingsignal characteristics (for example, a phase, a frequency, and anamplitude) equal or similar to those of the third touch electrodedriving signal TDS3.

In Case 1, the data signal Vdata may be a signal which is modulated onthe basis of the first touch electrode driving signal TDS1. The scansignal Vgate may be a signal which is modulated on the basis of thefirst touch electrode driving signal TDS1.

The above-mentioned time-free driving of the touch display device willbe described below in more detail.

FIG. 11 is a diagram illustrating a time-free driving system in thetouch display device according to one embodiment.

Referring to FIG. 11, the touch display device includes a display panelDISP in which a plurality of data lines DL and a plurality of gate linesGL are arranged and a plurality of touch electrodes TE are arranged, agate driving circuit GDC that is able to be electrically connected tothe plurality of gate lines GL and drives the plurality of gate linesGL, a data driving circuit DDC that is able to be electrically connectedto the plurality of data lines DL and drives the plurality of data linesDL, and a touch driving circuit TDC that is able to be electricallyconnected to the plurality of touch electrodes TE and drives theplurality of touch electrodes TE.

The touch display device may further include a display controller DCTRthat controls driving operations of the data driving circuit DDC and thegate driving circuit GDC and a touch controller TCTR that controls adriving operation of the touch driving circuit TDC or calculates whetherthere is a touch and/or touch coordinates using sensing data which isoutput from the touch driving circuit TDC.

The touch display device may further include a touch power circuit TPICand a power management circuit PMIC for supplying power.

The touch power circuit TPIC can supply an ON-level gate voltage VGH_Mand an OFF-level gate voltage VGL_M which are required for driving thegate lines GL to the gate driving circuit GDC.

The touch power circuit TPIC can supply a touch electrode driving signalTDS which is required for driving the touch electrodes TE to the touchdriving circuit TDC.

On the other hand, in view of a driving entity for the touch electrodesTE, the touch driving circuit TDC can supply touch electrode drivingsignals TDS1 and TDS3 for touch sensing to the touch electrodes TE whichare to be sensed among the plurality of touch electrodes TE on the basisof a modulated signal (for example, a pulse width modulated signal)received from the touch controller TCTR. The touch power circuit TPICcan also supply the modulated signal (for example, a pulse widthmodulated signal) received from the touch controller TCTR as a load-freedriving signal (a type of touch electrode driving signal) to the touchelectrodes TE which are not to be sensed among the plurality of touchelectrodes TE. Here, the touch electrode driving signals TDS1 and TDS2applied to the touch electrodes TE which are to be sensed and theload-free driving signal (which can be also considered to be a touchelectrode driving signal) applied to the touch electrodes TE which arenot to be sensed may be the same signal.

The power management circuit PMIC can supply various DC voltages (suchas AVDD, Vcom, VGH, and VGL) required for supply of signals from thetouch power circuit TPIC to the touch power circuit TPIC.

The power management circuit PMIC can supply various DC voltages (suchas AVDD and AVSS) required for data driving in the data driving circuitDDC to the data driving circuit DDC.

The touch controller TCTR can supply pulse width modulated (PWM) signalsfor outputting or generating various signals (for example, TDS) incircuits such as the touch power circuit TPIC, the touch driving circuitTDC, and the data driving circuit DDC. The touch controller TCTR can beembodied by, for example, a micro control unit (MCU) or a processor.

The touch display device may further include one or more level shiftersL/S that change voltage levels of various signals.

The one or more level shifters L/S may be embodied separately from thedata driving circuit DDC, the gate driving circuit GDC, the touchdriving circuit TDC, the touch power circuit TPIC, the power managementcircuit PMIC, the display controller DCTR, and the touch controller TCTRor may be included as one or more internal modules in the data drivingcircuit DDC, the gate driving circuit GDC, the touch driving circuitTDC, the touch power circuit TPIC, the power management circuit PMIC,the display controller DCTR, and the touch controller TCTR.

Referring to FIG. 11, the data driving circuit DDC may include a gammablock GMA that converts an image digital signal input from the displaycontroller DCTR or the like into an image analog signal.

Referring to FIG. 11, the touch power circuit TPIC is configured tosupply a D/A conversion control signal DACS required for converting animage digital signal into an image analog signal to the gamma block GMAin the data driving circuit DDC.

The D/A conversion control signal DACS can include, for example, a gammareference voltage EGBI_M and may further include a half drive voltageHVDD_M, which is a drive voltage of a middle level between the drivevoltage AVDD (which is a high-level voltage) and the base voltage AVSS(which is a low-level voltage).

The gamma reference voltage EGBI_M which is a D/A conversion controlsignal DACS can include a high gamma reference voltage and a low gammareference voltage which are input to both ends of a resistor string inthe gamma block GMA.

The half drive voltage HVDD_M which is another D/A conversion controlsignal DACS may be a voltage which is substantially half the drivevoltage AVDD.

As described above, the touch driving circuit TDC can output a firsttouch electrode driving signal TDS1 swinging with the first amplitudeAMP1 to the plurality of touch electrodes TE, output a second touchelectrode driving signal TDS2 corresponding to a DC voltage to theplurality of touch electrodes TE, or output a third touch electrodedriving signal TDS3 swinging with the third amplitude AMPS to all orsome of the plurality of touch electrodes TE.

Here, the first touch electrode driving signal TDS1 is a driving signalfor touch sensing and corresponds to a common voltage Vcom for display.The second touch electrode driving signal TDS2 corresponds to the commonvoltage Vcom for display. The third touch electrode driving signal TDS3corresponds to the driving signal for touch sensing.

In Case 1 in which display driving and touch driving are simultaneouslyperformed, when the first touch electrode driving signal TDS1 is outputto the plurality of touch electrodes TE, load-free driving for reducingunnecessary parasitic capacitance from being formed between theplurality of touch electrodes TE and the plurality of data lines DL isrequired.

For this purpose, the data driving circuit DDC can supply a data signalVdata for generating the same voltage variation state as the voltagevariation state of the touch electrodes TE due to the first touchelectrode driving signal TDS1 in the data lines DL to the data lines DL.

For this load-free driving, the data driving circuit DDC can use a gammamodulation technique.

More specifically, the data driving circuit DDC can convert an imagedigital signal into an image analog signal in response to the gammareference voltage EGBI_M of a modulated signal pattern swinging with apredetermined amplitude and output a data signal Vdata corresponding tothe image analog signal to the data lines DL.

The data driving circuit DDC includes a digital-analog converter DACthat converts an image digital signal into an image analog signal inresponse to the gamma reference voltage EGBI_M of a modulated signalpattern swinging with a predetermined amplitude and an output buffercircuit that outputs a data signal Vdata corresponding to the imageanalog signal to the data lines DL.

The gamma reference voltage EGBI_M of a modulated signal pattern may bea signal which is applied to the touch electrodes TE and which ismodulated in synchronization with the first touch electrode drivingsignal TDS1 swinging with the first amplitude AMP1.

The gamma reference voltage EGBI_M of a modulated signal pattern mayhave a frequency and a phase corresponding to those of the first touchelectrode driving signal TDS1. In some cases, the gamma referencevoltage EGBI_M may have an amplitude equal or similar to the firstamplitude AMP1 of the first touch electrode driving signal TDS1.

The data signal Vdata which is generated on the basis of the gammareference voltage EGBI_M of a modulated signal pattern may include avoltage variation part corresponding to the voltage variation of thefirst touch electrode driving signal TDS1.

For the gamma modulation technique of the data driving circuit DDC, thetouch power circuit TPIC can output the gamma reference voltage EGBI_Mhaving an amplitude corresponding to the first amplitude AMP1 of thefirst touch electrode driving signal TDS1 to the data driving circuitDDC at the driving timing corresponding to Case 1.

At the driving timing corresponding to Case 2, the touch power circuitTPIC can output the gamma reference voltage EGBI_M corresponding to a DCvoltage to the data driving circuit DDC.

At the driving timing corresponding to Case 3, the touch power circuitTPIC does not supply any gamma reference voltage EGBI_M of any patternto the data driving circuit DDC.

Referring to FIG. 11, in the touch display device, the display panelDISP, the data driving circuit DDC, the gate driving circuit GDC, thetouch driving circuit TDC, and the like can be connected to a DC groundvoltage GND.

FIGS. 12 to 14 are diagrams illustrating a signal transmission systembetween elements for the three cases of time-free driving in the touchdisplay device. Here, it is assumed that the touch driving circuit TDCand the data driving circuit DDC are integrated as a single drivingcircuit TDIC.

Referring to FIGS. 12 to 14, the touch power circuit TPIC receives adrive voltage AVDD which is a DC voltage, ON-level gate voltages VGH1and VGH2, and OFF-level gate voltages VGL1 and VGL2 from the powermanagement circuit PMIC.

Referring to FIG. 12, when display driving and touch driving aresimultaneously performed in the active time (Case 1), the touch powercircuit TPIC can supply the first touch electrode driving signal TDS1having the first amplitude AMP1 to the touch driving circuit TDC.

The touch power circuit TPIC can supply the half drive voltage HVDD_Mand the gamma reference voltage EGBI_M which swing in synchronizationwith the first touch electrode driving signal TDS1 to the gamma blockGMA of the data driving circuit DDC. Here, the half drive voltage HVDD_Mand the gamma reference voltage EGBI_M may have a frequency and a phasecorresponding to those of the first touch electrode driving signal TDS1.

The touch power circuit TPIC can supply an ON-level gate voltage VGH_Mand an OFF-level gate voltage VGL_M which swing in synchronization withthe first touch electrode driving signal TDS1 to the gate drivingcircuit GDC. Here, the ON-level gate voltage VGH_M and the OFF-levelgate voltage VGL_M may have a frequency and a phase corresponding tothose of the first touch electrode driving signal TDS1.

The ON-level gate voltage VGH_M and the OFF-level gate voltage VGL_M canbe changed via the level shifter L/S and the changed voltages can besupplied to the gate driving circuit GDC by the level shifter L/S. Thelevel shifter L/S is disposed outside the gate driving circuit GDC.Alternatively, the level shifter L/S may be disposed in the gate drivingcircuit GDC and change the ON-level gate voltage VGH_M and the OFF-levelgate voltage VGL_M received from the touch power circuit TPIC.

The touch driving circuit TDC can output the first touch electrodedriving signal TDS1 having the first amplitude AMP1 to the plurality oftouch electrodes TE.

Here, the first touch electrode driving signal TDS1 serves as a drivingsignal for touch sensing and also serves as a common voltage Vcom fordisplay.

The data driving circuit DDC can convert an image digital signal into animage analog signal in response to the gamma reference voltage EGBI_Mhaving a frequency and a phase corresponding to those of the first touchelectrode driving signal TDS1 and output a data signal Vdatacorresponding to the image analog signal to the data lines DL.

When the first touch electrode driving signal TDS1 is output to theplurality of touch electrodes TE, the gate driving circuit GDC cansupply a first OFF-level gate voltage VGL_M having a frequency and aphase corresponding to those of the first touch electrode driving signalTDS1 or supply a first ON-level gate voltage VGH_M which is offset bythe first OFF-level gate voltage VGL_M to the gate lines GL.

In Case 1, the display panel DISP may have characteristics that avoltage swings.

Referring to FIG. 13, when only display driving is performed in theactive time (Case 2), the touch power circuit TPIC can supply a secondtouch electrode driving signal TDS2 corresponding to a DC voltage to thetouch driving circuit TDC.

The touch power circuit TPIC can supply the half drive voltage HVDD_M ofa DC voltage pattern and the gamma reference voltage EGBI_M of a DCvoltage pattern to the gamma block GMA of the data driving circuit DDC.

The touch power circuit TPIC can supply the ON-level gate voltage VGH_Mand the OFF-level gate voltage VGL_M of a DC voltage pattern to the gatedriving circuit GDC.

The voltage levels of the ON-level gate voltage VGH_M and the OFF-levelgate voltage VGL_M of a DC voltage pattern can be changed via a levelshifter L/S and the changed voltages can be supplied to the gate drivingcircuit GDC by the level shifter L/S. The level shifter L/S is disposedoutside the gate driving circuit GDC. Alternatively, the level shifterL/S may be disposed in the gate driving circuit GDC and change thevoltage levels of the ON-level gate voltage VGH_M and the OFF-level gatevoltage VGL_M received from the touch power circuit TPIC.

The touch driving circuit TDC can supply the second touch electrodedriving signal TDS2 of a DC voltage pattern to the plurality of touchelectrodes TE.

Here, the second touch electrode driving signal TDS2 of a DC voltagepattern supplied to the plurality of touch electrodes TE may serve as acommon voltage for display driving. Accordingly, the plurality of touchelectrodes TE may serve as a common electrode.

The data driving circuit DDC can convert an image digital signal into animage analog signal in response to the gamma reference voltage EGBI_Mand the half drive voltage HVDD_M corresponding to a DC voltage andoutput a data signal Vdata corresponding to the image analog signal tothe data lines DL.

When the second touch electrode driving signal TDS2 is output to theplurality of touch electrodes TE, the gate driving circuit GDC cansupply a second OFF-level gate voltage VGL_M which is a DC voltage tothe gate lines GL or supply a second ON-level gate voltage VGH_M whichis a DC voltage to the gate lines GL.

In Case 2, the display panel DISP can have DC voltage characteristics.

Referring to FIG. 14, when touch driving is performed in the blank time(Case 3), the touch power circuit TPIC can supply a third touchelectrode driving signal TDS3 having the third amplitude AMPS to thetouch driving circuit TDC.

Since display driving is not required in the blank time, the touch powercircuit TPIC does not supply the half drive voltage HVDD_M and the gammareference voltage EGBI_M to the gamma block GMA of the data drivingcircuit DDC. That is, since touch driving is performed but displaydriving is not performed in the blank time in Case 3 of time-freedriving, the gamma reference voltage EGBI_M is not input to the datadriving circuit DDC.

The touch power circuit TPIC can supply an OFF-level gate voltage VGL_Mswinging in synchronization with the third touch electrode drivingsignal TDS3 to the gate driving circuit GDC. Here, the OFF-level gatevoltage VGL_M has a frequency and a phase corresponding to those of thethird touch electrode driving signal TDS3.

Since display driving is not required in the blank time, the touch powercircuit TPIC does not output the ON-level gate voltage VGH_M.

A voltage level of the OFF-level gate voltage VGL_M can be changed via alevel shifter L/S and the changed voltage can be supplied to the gatedriving circuit GDC by the level shifter L/S. The level shifter L/S isdisposed outside the gate driving circuit GDC. Alternatively, the levelshifter L/S may be disposed in the gate driving circuit GDC and changethe voltage level of the OFF-level gate voltage VGL_M received from thetouch power circuit TPIC.

In the blank time, the touch driving circuit TDC can output a thirdtouch electrode driving signal TDS3 having a third amplitude AMPSdifferent from the first amplitude AMP1 to all or some of the pluralityof touch electrodes TE.

Here, the third touch electrode driving signal TDS3 does not serve as acommon voltage for display but serves as a driving signal for touchsensing.

The third touch electrode driving signal TDS3 which is output from thetouch driving circuit TDC can be applied to all or some of the pluralityof touch electrodes TE and also be applied to other electrodes (forexample, other touch electrodes) or other lines (DL, GL) which arearranged in the display panel DISP for the purpose of load-free drivingby a switching circuit S/C.

More specifically, in the blank time, the third touch electrode drivingsignal TDS3 or a signal corresponding to the third touch electrodedriving signal TDS3 can be applied to all or some of the plurality ofdata lines DL. Here, the third touch electrode driving signal TDS3 orthe signal corresponding to the third touch electrode driving signalTDS3 which is applied to all or some of the plurality of data lines DLis a load-free driving signal that can reduce parasitic capacitance frombeing formed between the corresponding touch electrode TE and thecorresponding data line DL and remove a load (an RC delay) in thecorresponding touch electrode TE and the corresponding touch line TL.

When the third touch electrode driving signal TDS3 is supplied to theplurality of touch electrodes TE, the gate driving circuit GDC cansupply a third OFF-level gate voltage VGL_M having a frequency and aphase corresponding to those of the third touch electrode driving signalTDS3 to the gate lines GL.

In the blank time, the third touch electrode driving signal TDS3 or thesignal (the third OFF-level gate voltage) corresponding to the thirdtouch electrode driving signal TDS3 can be applied to all or some of theplurality of gate lines GL.

Here, the third touch electrode driving signal TDS3 or the signalcorresponding to the third touch electrode driving signal TDS3 which isapplied to all or some of the plurality of gate lines GL is a load-freedriving signal that can reduce parasitic capacitance from being formedbetween the corresponding touch electrode TE and the corresponding gateline GL and remove a load (an RC delay) in the corresponding touchelectrode TE and the corresponding touch line TL.

In Case 3, the display panel DISP can have characteristics that avoltage swings.

Case 1 in which display driving and touch driving are simultaneouslyperformed among three cases of time-free driving (Case 1, Case 2, andCase 3) will be described below in more detail.

FIG. 15 is a diagram illustrating an example of a gamma block GMA forperforming time-free driving TFD on the data lines DL using the gammamodulation technique in the time-free driving (TFD) system of the touchdisplay device according to one embodiment. FIG. 16 is a diagramillustrating voltage levels and characteristics of the gamma referencevoltages EGBI1_M, EGBI2_M, EGBI3_M, and EGBI4_M which are used in thegamma block GMA for performing time-free driving on the data lines DLusing the gamma modulation technique in the time-free driving system ofthe touch display device according to one embodiment.

In the following description, it is assumed that the data lines DL aredriven on the basis of polarity inversion driving.

The gamma block GMA in the data driving circuit DDC can include adigital-to-analog converter DAC that converts an image digital signal toan image analog signal having a positive polarity or a negative polarityusing the gamma reference voltages EGBILM, EGBI2_M, EGBI3_M, andEGBI4_M.

The digital-to-analog converter DAC includes a first conversion part (apositive conversion part) and a second conversion part (a negativeconversion part).

The first conversion part of the digital-to-analog converter DACincludes a first resistor string P-RS in which a plurality of resistorsare connected in series and a first switch P-SW that selects an imageanalog voltage having a positive polarity on the basis of an imagedigital signal. The second conversion part of the digital-to-analogconverter DAC includes a second resistor string N-RS in which aplurality of resistors are connected in series and a second switch N-SWthat selects an image analog voltage having a negative polarity on thebasis of an image digital signal.

The gamma block GMA in the data driving circuit DDC can further includea multiplexer MUX that selects an image analog voltage having a positivepolarity and an image analog voltage having a negative polarity, a firstoutput buffer circuit P-BUF that outputs a first data signal Vdatacorresponding to the image analog signal having a positive polarity tothe data lines DL, and a second output buffer circuit N-BUF that outputsa second data signal Vdata corresponding to the image analog signalhaving a negative polarity to the data lines DL.

Referring to FIGS. 15 and 16, when the data driving circuit DDC performspolarity inversion driving, the gamma reference voltage EGBI_M of amodulated signal pattern can include a first gamma reference voltageEGBI1_M and a second gamma reference voltage EGBI2_M which are appliedto both ends of the resistor string having a positive polarity P-RS andinclude a third gamma reference voltage EGBI3_M and a fourth gammareference voltage EGBI4_M which are applied to both ends of the resistorstring having a negative polarity N-RS.

The four gamma reference voltages EGBI1_M, EGBI2_M, EGBI3_M, and EGBI4_Mmay be signals which are generated by modulating the frequency and thephase of the first touch electrode driving signal TDS1 insynchronization.

Each of the four gamma reference voltages EGBI1_M, EGBI2_M, EGBI3_M, andEGBI4_M is a variable voltage and can have an amplitude equal or similarto the first amplitude AMP1 of the first touch electrode driving signalTDS1.

In other words, the digital-to-analog converter DAC in the data drivingcircuit DDC can receive the first gamma reference voltage EGBI1_M, thesecond gamma reference voltage EGBI2_M, the third gamma referencevoltage EGBI3_M, and the fourth gamma reference voltage EGBI4_M having afrequency and a phase corresponding to those of the first touchelectrode driving signal TDS1 and convert an image digital signal into afirst image analog signal (an image analog signal having a positivepolarity) in response to the first gamma reference voltage EGBI1_M andthe second gamma reference voltage EGBI2_M or convert an image digitalsignal into a second image analog signal (an image analog signal havinga negative polarity) in response to the third gamma reference voltageEGBI3_M and the fourth gamma reference voltage EGBI4_M.

The first output buffer circuit P-BUF can receive the first image analogsignal and output a first data signal Vdata to the data lines DL.

The second output buffer circuit N-BUF can receive the second imageanalog signal and output a second data signal Vdata to the data linesDL.

The first data signal Vdata is a data signal Vdata having a positivepolarity which is output to the data lines DL in the i-th frame. Thesecond data signal Vdata is a data signal Vdata having a negativepolarity which is output to the data lines DL in the (i+1)-th frame.

Referring to FIGS. 15 and 16, the first gamma reference voltage EGBI1_Mis a positive-high gamma reference voltage, the second gamma referencevoltage EGBI2_M is a positive-low gamma reference voltage, the thirdgamma reference voltage EGBI3_M is a negative-high gamma referencevoltage, and the fourth gamma reference voltage EGBI4_M is anegative-low gamma reference voltage.

The first gamma reference voltage EGBI1_M, the second gamma referencevoltage EGBI2_M, the third gamma reference voltage EGBI3_M, and thefourth gamma reference voltage EGBI4_M are modulated signals which swingin synchronization with the first touch electrode driving signal TDS1and can have a frequency and a phase corresponding to those of the firsttouch electrode driving signal TDS1.

The first gamma reference voltage EGBI1_M, the second gamma referencevoltage EGBI2_M, the third gamma reference voltage EGBI3_M, the fourthgamma reference voltage EGBI4_M can have an amplitude AMP correspondingto the first amplitude AMP1 of the first touch electrode driving signalTDS1.

The first gamma reference voltage EGBI1_M can be set to a voltage higherthan the second gamma reference voltage EGBI2_M. The second gammareference voltage EGBI2_M can be set to a voltage higher than the thirdgamma reference voltage EGBI3_M. The third gamma reference voltageEGBI3_M can be set to a voltage higher than the fourth gamma referencevoltage EGBI4_M.

On the other hand, referring to FIG. 15, the first output buffer circuitP-BUF can operate with the drive voltage AVDD applied to a PH node andthe half drive voltage HVDD_M applied to a PL node.

The second output buffer circuit N-BUF can operate with the half drivevoltage HVDD_M applied to an NH node and the base voltage AVSS appliedto an NL node.

The drive voltage AVDD applied to the first output buffer circuit P-BUFand the half drive voltage HVDD_M applied to the second output buffercircuit N-BUF are voltages that perform the same function (a bufferdrive voltage). The half drive voltage HVDD_M applied to the firstoutput buffer circuit P-BUF and the base voltage AVSS applied to thesecond output buffer circuit N-BUF are voltages that perform the samefunction (a buffer base voltage).

The drive voltage AVDD may be a DC voltage. The base voltage AVSS may bea DC voltage which is lower than the drive voltage AVDD. For example,the base voltage AVSS may be 0 V.

The half drive voltage HVDD_M may be a signal of which the voltageswings between the drive voltage AVDD and the base voltage AVSS.

The half drive voltage HVDD_M may be a signal having a frequency and aphase corresponding to those of the first touch electrode driving signalTDS1. Accordingly, the half drive voltage HVDD_M can have a frequencyand a phase corresponding to those of the first gamma reference voltageEGBI1_M, the second gamma reference voltage EGBI2_M, the third gammareference voltage EGBI3_M, and the fourth gamma reference voltageEGBI4_M.

In some cases, the half drive voltage HVDD_M can have an amplitudecorresponding to the first amplitude AMP1 of the first touch electrodedriving signal TDS1. Accordingly, the half drive voltage HVDD_M can havean amplitude corresponding to those of the first gamma reference voltageEGBI1_M, the second gamma reference voltage EGBI2_M, the third gammareference voltage EGBI3_M, and the fourth gamma reference voltageEGBI4_M.

The first gamma reference voltage EGBI1_M and the second gamma referencevoltage EGBI2_M can be set to voltages which are higher than the halfdrive voltage HVDD_M. The third gamma reference voltage EGBI3_M and thefourth gamma reference voltage EGBI4_M can be set to voltages which arelower than the half drive voltage HVDD_M.

A low-level voltage of the fourth gamma reference voltage EGBI4_M can beset to be higher than the base voltage AVSS. Particularly, a differenceΔV between the low-level voltage of the first gamma reference voltageEGBI1_M and the drive voltage AVDD can be set to be equal to or greaterthan the amplitude AMP of the first gamma reference voltage EGBILM.

Referring to FIG. 15, a voltage AVSS_M having an amplitude correspondingto the first amplitude AMP1 of the first touch electrode driving signalTDS1 can be applied to an NHV node which is commonly connected to a node(a PL node) at which the half drive voltage HVDD_M is applied to thefirst output buffer circuit P-BUF and a node (an NH node) at which thehalf drive voltage HVDD_M is applied to the second output buffer circuitN-BUF via a capacitor Ch.

The half drive voltage HVDD_M serves as a base voltage of a low levelfor the first output buffer circuit P-BUF and serves as a drive voltageof a high level for the second output buffer circuit N-BUF. In thisregard, the capacitor Ch connected to the NHV node can help voltagestabilization of the NHV node and the half drive voltage HVDD_M.

FIG. 17 is a diagram illustrating waveforms of principal signals TDS1,Vdata, VGL_M, VGH_M, and Vgate for time-free driving when the frequencyof the first touch electrode driving signal TDS1 is high in the touchdisplay device according to one embodiment. FIG. 18 is a diagramillustrating waveforms of principal signals TDS1, Vdata, VGL_M, VGH_M,and Vgate for time-free driving when the frequency of the first touchelectrode driving signal TDS1 is low in the touch display deviceaccording to one embodiment.

The frequency of the first touch electrode driving signal TDS1 may beset to be high or low. That is, the period T of the first touchelectrode driving signal TDS1 may be set to be short or long.

As illustrated in FIG. 17, the period T of the first touch electrodedriving signal TDS1 may be shorter than a predetermined horizontal time1H or a data voltage application period. As illustrated in FIG. 18, theperiod T of the first touch electrode driving signal TDS1 may be longerthan the predetermined horizontal time 1H or the data voltageapplication period. Here, the predetermined horizontal time may be 1H,2H, 3H, or the like, wherein 1H, 2H, 3H, etc., may denote the time fordisplaying 1 horizontal line, 2 horizontal lines, 3 horizontal lines,etc., of subpixels in the display device. In the following description,it is assumed that the predetermined horizontal time is 1H.

Referring to FIG. 17, the first touch electrode driving signal TDS1 is asignal of which a voltage level varies periodically, the period T or thewidth of a high-level voltage period of the first touch electrodedriving signal TDS1 may be shorter than one horizontal time 1H.

In this case, in a high-level voltage period of a data signal Vdata fordisplaying an image which is supplied to at least one data line DL or ahigh-level voltage period of a scan signal Vgate which is supplied to atleast one gate line GL, the voltage level of the first touch electrodedriving signal TDS1 may vary one or more times.

Referring to FIG. 18, the period T or the width of the high-levelvoltage period of the first touch electrode driving signal TDS1 may belonger than one horizontal time 1H or the data voltage applicationperiod.

In this case, in the period T or the high-level voltage period of thefirst touch electrode driving signal TDS1, the voltage level of the datasignal Vdata for displaying an image which is supplied to at least onedata line DL may vary one or more times or the voltage level of the scansignal Vgate which is supplied to at least one gate line GL may vary oneor more times.

Signal waveforms will be described below in more detail with referenceto FIGS. 17 and 18.

Referring to FIGS. 17 and 18, when display driving and touch driving aresimultaneously performed on the basis of the time-free driving system,the data signal Vdata may have a signal pattern in which first pulsesPULSE1 having a first pulse width W1 and second pulses PULSE2 having asecond pulse width W2 are combined. Here, the second pulse width W2 maybe greater than the first pulse width W1.

Referring to FIGS. 17 and 18, the data signal Vdata may have a voltagevarying between the drive voltage AVDD and the base voltage AVSS.

As illustrated in FIG. 17, when the period T of the first touchelectrode driving signal TDS1 is shorter than a predetermined horizontaltime (for example, 1H), the first pulses PULSE1 in the data signal Vdatamay include a part having an amplitude corresponding to the firstamplitude AMP1 of the first touch electrode driving signal TDS1. Thefirst pulse width W1 of the first pulses PULSE1 may correspond to thepulse width of the first touch electrode driving signal TDS1.

As illustrated in FIG. 18, when the period T of the first touchelectrode driving signal TDS1 is longer than a predetermined horizontaltime (for example, 1H), the second pulses PULSE2 in the data signalVdata may include a part having an amplitude corresponding to the firstamplitude AMP1 of the first touch electrode driving signal TDS1. Thesecond pulse width W2 of the second pulses PULSE2 may correspond to thepulse width of the first touch electrode driving signal TDS1.

Referring to FIGS. 17 and 18, a frequency and a phase of an OFF-levelgate voltage VGL_M which is supplied from the touch power circuit TPICto the gate driving circuit GDC correspond to those of the first touchelectrode driving signal TDS1. A frequency and a phase of an ON-levelgate voltage VGH_M which is supplied from the touch power circuit TPICto the gate driving circuit GDC correspond to those of the first touchelectrode driving signal TDS1.

Referring to FIGS. 17 and 18, the OFF-level gate voltage VGL_M and theON-level gate voltage VGH_M may have the same amplitude as the firstamplitude AMP1 of the first touch electrode driving signal TDS1 orsubstantially the same amplitude within an allowable range.

Referring to FIG. 17, the scan signal Vgate which is supplied to thegate line GL may be the OFF-level gate voltage VGL_M in a period otherthan the horizontal time (1H) in which the corresponding gate line GL isdriven with the ON-level gate voltage VGH_M. The scan signal Vgate maybe the ON-level gate voltage VGH_M in the horizontal time (1H) in whichthe corresponding gate line GL is driven with the ON-level gate voltageVGH_M. The scan signal Vgate may have a pattern in which a voltage(ΔVgate) corresponding to the amplitude required for turning on atransistor included in the corresponding pixel, which is supplied to thegate electrode of the transistor, is added to the ON-level gate voltageVGH_M. Here, the voltage (ΔVgate) corresponding to the amplituderequired for opening the corresponding gate line GL may be a voltagedifference between a high-level gate voltage VGH and a low-level gatevoltage VGL of a DC voltage pattern.

Referring to FIG. 17, the scan signal Vgate which is supplied to thegate line GL has a pattern in which the OFF-level gate voltage VGL_M ofa modulated signal pattern is superimposed on the voltage ΔVgatecorresponding to the amplitude required for turning on a transistor inthe horizontal time (1H) in which the corresponding gate line GL isdriven with the gate high voltage VGH and has a pattern of the OFF-levelgate voltage VGL_M of a modulated signal pattern in a time other thanthe horizontal time (1H). Here, the OFF-level gate voltage VGL_M of amodulated signal pattern has a frequency and a phase corresponding tothose of the first touch electrode driving signal TDS1.

Referring to FIG. 18, the scan signal Vgate which is applied to the gatelines GL has a pattern in which the voltage ΔVgate corresponding to theamplitude required for opening the corresponding gate line GL issuperimposed on the OFF-level gate voltage VGL_M of a modulated signalpattern in the horizontal time (1H) in which the corresponding gate lineGL is open, and has a pattern of the OFF-level gate voltage VGL_M of amodulated signal pattern in a time other than the horizontal time (1H).Here, the OFF-level gate voltage VGL_M of a modulated signal pattern hasa frequency and a phase corresponding to those of the first touchelectrode driving signal TDS1.

As described above, the touch display device can employ a gammamodulation method as a method of simultaneously executing displaydriving and touch driving.

In this case, a data signal Vdata and a scan signal Vgate which aremodulated to have a frequency and a phase corresponding to those of thefirst touch electrode driving signal TDS1 in accordance with gammamodulation are supplied to the display panel DISP to which a groundvoltage of a DC voltage is applied.

On the other hand, as described above, the touch display device mayemploy a ground modulation method in addition to a gamma modulationmethod as the method of simultaneously executing display driving andtouch driving.

In the ground modulation method, the data signal Vdata and the scansignal Vgate which are supplied to the display panel DISP have afrequency and a phase corresponding to those of the first touchelectrode driving signal TDS1 on the display panel DISP by causing theground voltage supplied to the display panel DISP to swing to correspondto the frequency and the phase of the first touch electrode drivingsignal TDS1.

In other words, the gamma modulation method is a method of supplying thedisplay relevant signals Vdata and Vgate to the display panel DISP in amodulated signal pattern corresponding to the first touch electrodedriving signal TDS1 in a state in which the DC ground voltage is appliedto the display panel DISP.

On the other hand, the ground modulation method is a method of supplyingthe display relevant signals Vdata and Vgate to the display panel DISPwithout modulation, whereby the display relevant signals Vdata and Vgatesupplied to the display panel DISP have a modulated signal patterncorresponding to the first touch electrode driving signal TDS1 becausethe ground voltage of a modulated signal pattern is applied to thedisplay panel DISP.

In the following description, for the purpose of convenience ofexplanation, the first and third touch electrode driving signals TDS1and TDS3 of which the voltage level varies are referred to as a touchelectrode driving signal TDS.

FIG. 19 is a diagram illustrating a process of generating a scan signalVgate for gate driving in the touch display device according to oneembodiment. FIG. 20 is a diagram illustrating an ON-clock signal ON_CLK,an OFF-clock signal OFF_CLK, and a scan signal Vgate which areassociated with gate driving in the touch display device according toone embodiment.

Referring to FIG. 19, the display controller DCTR outputs an ON-clocksignal ON_CLK and an OFF-clock signal OFF_CLK to a clock generator CGRfor the purpose of gate driving.

The clock generator CGR generates two or more gate clock signals GCLK1,GCLK2, . . . on the basis of the ON-clock signal ON_CLK and theOFF-clock signal OFF_CLK and outputs the generated gate clock signals.For example, the clock generator CGR may be a level shifter L/S.

The clock generator CGR can generate two or more gate clock signalsGCLK1, GCLK2, . . . depending on a gate driving system.

The gate driving circuit GDC generates scan signals Vgate1, Vgate2, . .. on the basis of the two or more gate clock signals GCLK1, GCLK2, . . .and sequentially outputs the generated scan signals to the plurality ofgate lines GL1, GL2, . . . .

Each of the scan signals Vgate1, Vgate2, . . . is a clock pulse suitablefor the corresponding timing out of a plurality of clock pulses includedin one gate clock signal.

In FIG. 20, it is assumed that gate driving is performed using four gateclock signals GCLK1, GCLK2, GCLK3, and GCLK4.

Referring to FIG. 20, the high-level period Pon of the ON-clock signalON_CLK is repeated with a constant period T1. The high-level period Poffof the OFF-clock signal OFF_CLK is repeated with a constant period T1.The ON-clock signal ON_CLK and the OFF-clock signal OFF_CLK have thesame frequency (f1=1/T1).

The clock generator CGR can generate the gate clock signals GCLK1,GCLK2, GCLK3, and GCLK4 using the ON-clock signal ON_CLK and theOFF-clock signal OFF_CLK.

Referring to FIG. 20, the gate clock signals GCLK1, GCLK2, GCLK3, andGCLK4 rise in the high-level period Pon of the ON-clock signal ON_CLK.That is, rising sections Pup of the gate clock signals GCLK1, GCLK2,GCLK3, and GCLK4 correspond to the high-level period Pon of the ON-clocksignal ON_CLK.

Referring to FIG. 20, the gate clock signals GCLK1, GCLK2, GCLK3, andGCLK4 fall in the high-level period Poff of the OFF-clock signalOFF_CLK. That is, falling sections Pdown of the gate clock signalsGCLK1, GCLK2, GCLK3, and GCLK4 correspond to the high-level period Poffof the OFF-clock signal OFF_CLK.

The scan signals Vgate1, Vgate2, Vgate3, Vgate 4, . . . can be generatedon the basis of the gate clock signals GCLK1, GCLK2, GCLK3, and GCLK4which are generated as described above.

FIGS. 21 and 22 are diagrams illustrating a case in which a voltagelevel of a touch electrode driving signal TDS varies in the high-levelsection Poff of the OFF-clock signal OFF_CLK and an image defect of aline pattern based thereon in the touch display device according to oneembodiment.

Referring to FIG. 21, the frequency f1 of the OFF-clock signal OFF_CLKmay be different from the frequency f2 of the touch electrode drivingsignal TDS. Accordingly, a situation in which the voltage level of thetouch electrode driving signal TDS varies in the high-level period Poffof the OFF-clock signal OFF_CLK may occur.

Similarly, since the frequency f1 of the ON-clock signal ON_CLK isdifferent from the frequency f2 of the touch electrode driving signalTDS, a situation in which the voltage level of the touch electrodedriving signal TDS varies in the high-level period Pon of the ON-clocksignal ON_CLK may occur.

Referring to FIG. 22, when the voltage level of the touch electrodedriving signal TDS varies in the high-level period Poff of the OFF-clocksignal OFF_CLK and the high-level period Pon of the ON-clock signalON_CLK (2200), the data lines DL under gamma modulation for simultaneousdriving may be affected and an image defect of a line pattern may occurin the display panel DISP.

In other words, an image defect of subpixels included in a line block2210 in which the gate lines GL which are supplied with the scan signalVgate corresponding to the high-level period Poff of the OFF-clocksignal OFF_CLK and the high-level period Pon of the ON-clock signalON_CLK overlapping the variation of the voltage level of the touchelectrode driving signal TDS are arranged may occur.

Even when the voltage level of the touch electrode driving signal TDSvaries in the rising sections Pup and the falling sections Pdown of thegate clock signals GCLK1, GCLK2, . . . , the above-mentioned imagedefect of a line pattern may occur.

Even when the voltage level of the touch electrode driving signal TDSvaries in the rising sections Pup and the falling sections Pdown of thescan signals Vgate1, Vgate2, . . . , the above-mentioned image defect ofa line pattern may occur.

Since touch driving and display driving are simultaneously performed asdescribed above, touch driving affects display driving to cause an imagedefect.

In the following description, a driving method for reducing an imagedefect of a line pattern which is caused due to timing mismatch betweenthe gate driving relevant signals ON_CLK, OFF_CLK, GCLK, and Vgate andthe touch electrode driving signal TDS will be described.

FIGS. 23A and 23B are diagrams illustrating a driving method forreducing an image defect of a line pattern from occurring due to timingmismatch between the gate driving relevant signals ON_CLK, OFF_CLK,GCLK, and Vgate and the touch electrode driving signal TDS in the touchdisplay device according to one embodiment.

Referring to FIGS. 23A and 23B, the touch driving circuit TDC outputsthe touch electrode driving signal TDS of which the voltage level variesin a period other than the high-level period Pon of the ON-clock signalON_CLK to one or more of the plurality of touch electrodes TE.

The touch driving circuit TDC outputs the touch electrode driving signalTDS of which the voltage level varies in a period other than thehigh-level period Poff of the OFF-clock signal OFF_CLK to one or more ofthe plurality of touch electrodes TE.

The touch driving circuit TDC outputs the touch electrode driving signalTDS of which the voltage level varies in a section other than the risingsections Pup and the falling sections Pdown of the gate clock signalsGCLK1, GCLK2, . . . to one or more of the plurality of touch electrodesTE.

The touch driving circuit TDC outputs the touch electrode driving signalTDS of which the voltage level varies in a section other than the risingsections Pup and the falling sections Pdown of the scan signals Vgate1,Vgate2, . . . to one or more of the plurality of touch electrodes TE.

The touch controller TCTR can perform control such that the voltagelevel of the touch electrode driving signal TDS varies in a period otherthan the high-level period Pon of the ON-clock signal ON_CLK. Here, whenthe voltage level of the touch electrode driving signal TDS varies in aperiod other than the high-level period Pon of the ON-clock signalON_CLK, it means that the high-level period Pon of the ON-clock signalON_CLK and the voltage level variation section of the touch electrodedriving signal TDS are different timings.

The touch controller TCTR can perform control such that the voltagelevel of the touch electrode driving signal TDS varies in a period otherthan the high-level period Poff of the OFF-clock signal OFF_CLK. Here,when the voltage level of the touch electrode driving signal TDS variesin a period other than the high-level period Poff of the OFF-clocksignal OFF_CLK, it means that the high-level period Poff of theOFF-clock signal OFF_CLK and the voltage level variation section of thetouch electrode driving signal TDS are different timings.

The touch controller TCTR can perform control such that the voltagelevel of the touch electrode driving signal TDS varies in a sectionother than the rising sections Pup and the falling sections Pdown of thegate clock signals GCLK1, GCLK2, . . . . Here, when the voltage level ofthe touch electrode driving signal TDS varies in a section other thanthe rising sections Pup and the falling sections Pdown of the gate clocksignals GCLK1, GCLK2, . . . , it means that the rising sections Pup andthe falling sections Pdown of the gate clock signals GCLK1, GCLK2, . . .and the voltage level variation section of the touch electrode drivingsignal TDS are different timings.

The touch controller TCTR can perform control such that the voltagelevel of the touch electrode driving signal TDS varies in a sectionother than the rising sections Pup and the falling sections Pdown of thescan signals Vgate1, Vgate2, . . . . Here, when the voltage level of thetouch electrode driving signal TDS varies in a section other than therising sections Pup and the falling sections Pdown of the scan signalsVgate1, Vgate2, . . . , it means that the rising sections Pup and thefalling sections Pdown of the scan signals Vgate1, Vgate2, . . . and thevoltage level variation section of the touch electrode driving signalTDS are different timings.

As illustrated in FIG. 23A, the touch display device can perform controlsuch that the high-level period Pon of the ON-clock signal ON_CLK andthe high-level period Poff of the OFF-clock signal OFF_CLK are differenttimings. That is, the touch display device can perform control such thatthe high-level period Pon of the ON-clock signal ON_CLK and thehigh-level period Poff of the OFF-clock signal OFF_CLK do not overlapeach other and do not match each other.

The high-level period Pon of the ON-clock signal ON_CLK is associatedwith the rising sections Pup of the scan signals Vgate1, Vgate2, Vgate3, Vgate4, . . . , and the high-level period Poff of the OFF-clocksignal OFF_CLK is associated with the falling sections Pdown of the scansignals Vgate1, Vgate2, Vgate 3, Vgate4, In some cases, the ON-clocksignal ON_CLK and the OFF-clock signal OFF_CLK may change to a negativesignal pattern. In this case, the low-level period of the ON-clocksignal ON_CLK may be associated with the rising sections Pup of the scansignals Vgate1, Vgate2, Vgate 3, Vgate4, . . . , and the low-levelperiod of the OFF-clock signal OFF_CLK may be associated with thefalling sections Pdown of the scan signals Vgate1, Vgate2, Vgate 3,Vgate4, . . . .

In consideration of the relationship between two clock signals ON_CLKand OFF_CLK and the scan signals Vgate1, Vgate2, Vgate 3, Vgate4, . . ., the falling section Pdown of the first scan signal Vgate1 which issupplied to the first gate line GL1 of the plurality of gate lines GLand the rising section Pup of another scan signal (for example, Vgate3)which is supplied to a gate line (for example, GL3) other than the firstgate line GL1 may be different timings.

As illustrated in FIG. 23B, the touch display device can perform controlsuch that the high-level period Pon of the ON-clock signal ON_CLK andthe high-level period Poff of the OFF-clock signal OFF_CLK correspond toeach other. Here, when the high-level period Pon of the ON-clock signalON_CLK and the high-level period Poff of the OFF-clock signal OFF_CLKcorrespond to each other, it means that the high-level period Pon of theON-clock signal ON_CLK and the high-level period Poff of the OFF-clocksignal OFF_CLK are temporally the same period or are periods whichpartially temporally overlap each other.

In consideration of the relationship between two clock signals ON_CLKand OFF_CLK and the scan signals Vgate1, Vgate2, Vgate 3, Vgate4, . . ., the falling section Pdown of the first scan signal Vgate1 which issupplied to the first gate line GL1 of the plurality of gate lines GLand the rising section Pup of a third scan signal Vgate3 which issupplied to a third gate line GL3 other than the first gate line GL1 ofthe plurality of gate lines may correspond to each other.

Here, the first gate line GL1 and the third gate line GL3 which aredifferent from each other can overlap the same touch electrode, e.g.touch electrode TE2 described herein below in connection with FIGS. 27and 28. One or more other gate lines GL2 may be disposed between thefirst gate line GL1 and the third gate line GL3. On the other hand, thefirst gate line GL1 and the third gate line GL3 may be neighboring gatelines.

In consideration of the relationship between two clock signals ON_CLKand OFF_CLK and the scan signals Vgate1, Vgate2, Vgate 3, Vgate4, . . ., the falling section Pdown of the second scan signal Vgate2 which issupplied to the second gate line GL2 of the plurality of gate lines GLmay correspond to the rising section Pup of a fourth scan signal Vgate4which is supplied to a fourth gate line GL4 other than the second gateline GL2.

Here, the second gate line GL2 and the fourth gate line GL4 which aredifferent from each other can overlap the same touch electrode, e.g.touch electrode TE2 described herein below in connection with FIGS. 27and 28. One or more other gate lines GL3 may be disposed between thesecond gate line GL2 and the fourth gate line GL4. On the other hand,the second gate line GL2 and the fourth gate line GL4 may be neighboringgate lines.

A control method based on the relationship between the frequency f1 ofthe ON-clock signal ON_CLK and the OFF-clock signal OFF_CLK and thefrequency f2 of the touch electrode driving signal TDS will be describedbelow. For the purpose of convenience of explanation, the OFF-clocksignal OFF_CLK will be described as a reference.

FIG. 24 is a diagram illustrating control for allowing the voltage levelof the touch electrode driving signal TDS to vary in a period other thanthe high-level period Poff of the OFF-clock signal OFF_CLK when thefrequency f2 of the touch electrode driving signal TDS and the frequencyf1 of the OFF-clock signal OFF_CLK are different from each other in thetouch display device according to one embodiment.

Referring to FIG. 24, the frequency f2 of the touch electrode drivingsignal TDS may be different from the frequency f1 of the ON-clock signalON_CLK and the OFF-clock signal OFF_CLK.

Particularly, the frequency f2 of the touch electrode driving signal TDSmay be other than N or 1/N times the frequency f1 of the ON-clock signalON_CLK and the OFF-clock signal OFF_CLK.

Then, a section 2410 in which the voltage level of the touch electrodedriving signal TDS rises is necessarily present in the high-level periodPon of the ON-clock signal ON_CLK and the high-level period Poff of theOFF-clock signal OFF_CLK.

In such a section 2410, the touch electrode driving signal TDS may risewith a delay after the high-level period Pon of the ON-clock signalON_CLK and the high-level period Poff of the OFF-clock signal OFF_CLKhave passed depending on adjustment of a duty ratio.

A section 2420 in which the voltage level of the touch electrode drivingsignal TDS falls is necessarily present in the high-level period Pon ofthe ON-clock signal ON_CLK and the high-level period Poff of theOFF-clock signal OFF_CLK.

In such a section 2420, the touch electrode driving signal TDS may fallbefore the high-level period Pon of the ON-clock signal ON_CLK and thehigh-level period Poff of the OFF-clock signal OFF_CLK have starteddepending on adjustment of a duty ratio.

As described above, when the frequency f2 of the touch electrode drivingsignal TDS is different from the frequency f1 of the OFF-clock signalOFF_CLK and control is performed such that the voltage level of thetouch electrode driving signal TDS varies in a period other than thehigh-level period Poff of the OFF-clock signal OFF_CLK, the touchelectrode driving signal TDS can have variable duty ratios DR1, DR2, . .. .

For example, referring to FIG. 24, the touch electrode driving signalTDS includes a first signal section having a first duty ratio DR1 and asecond signal section having a second duty ratio DR2 which is differentfrom the first duty ratio DR1.

When the second signal section of the touch electrode driving signal TDShas the second duty ratio DR2 which is different from the first dutyratio DR1, the voltage level in the second signal section of the touchelectrode driving signal TDS can vary in a period other than thehigh-level period Pon of the ON-clock signal ON_CLK and the high-levelperiod Poff of the OFF-clock signal OFF_CLK.

For example, referring to FIG. 24, the touch electrode driving signalTDS includes a first signal section having the first duty ratio DR1 anda third signal section having a third duty ratio DR3 which is differentfrom the first duty ratio DR1.

When the third signal section of the touch electrode driving signal TDShas the third duty ratio DR3 which is different from the first dutyratio DR1, the voltage level in the third signal section of the touchelectrode driving signal TDS can vary in a period other than thehigh-level period Pon of the ON-clock signal ON_CLK and the high-levelperiod Poff of the OFF-clock signal OFF_CLK.

On the other hand, a method of performing control such that the voltagelevel of the touch electrode driving signal TDS varies in a period otherthan the high-level period Poff of the OFF-clock signal OFF_CLK when thefrequency f1 of the OFF-clock signal OFF_CLK is N or 1/N times thefrequency f2 of the touch electrode driving signal TDS will be describedbelow.

FIGS. 25A and 25B are diagrams illustrating control for allowing thevoltage level of the touch electrode driving signal TDS to vary in aperiod other than the high-level period Poff of the OFF-clock signalOFF_CLK when the frequency f1 of the OFF-clock signal OFF_CLK doublesthe frequency f2 of the touch electrode driving signal TDS in the touchdisplay device according to one embodiment. FIGS. 26A and 26B arediagrams illustrating control for allowing the voltage level of thetouch electrode driving signal TDS to vary in a period other than thehigh-level period Poff of the OFF-clock signal OFF_CLK when thefrequency f1 of the OFF-clock signal OFF_CLK quadruples the frequency f2of the touch electrode driving signal TDS in the touch display device.

Referring to FIGS. 25A and 25B, the voltage level of the OFF-clocksignal OFF_CLK varies in a first period T1. The voltage level of thetouch electrode driving signal TDS varies in a second period T2.

The second period T2 of the touch electrode driving signal TDS doublesthe first period T1 of the OFF-clock signal OFF_CLK (T2=2×T1).

Accordingly, the frequency f1 of the OFF-clock signal OFF_CLK doublesthe frequency f2 of the touch electrode driving signal TDS(f1=1/T1=1/(T2/2)=2(1/T2)=2f2).

Referring to FIGS. 26A and 26B, the second period T2 of the touchelectrode driving signal TDS quadruples the first period T1 of theOFF-clock signal OFF_CLK (T2=4×T1) according to one embodiment.

Accordingly, the frequency f1 of the OFF-clock signal OFF_CLK quadruplesthe frequency f2 of the touch electrode driving signal TDS(f1=1/T1=1/(T2/4)=4(1/T2)=4f2).

As illustrated in FIGS. 25A and 26A, when the frequency f1 of theOFF-clock signal OFF_CLK is N times the frequency f2 of the touchelectrode driving signal TDS (where N is a natural number), control canbe performed such that the voltage level of the touch electrode drivingsignal TDS does not vary in the high-level period Poff of the OFF-clocksignal OFF_CLK by setting a rising time point Tr2 of the touch electrodedriving signal TDS to be later than a falling time point Tfl of theOFF-clock signal OFF_CLK.

As illustrated in FIGS. 25B and 26B, when the frequency f1 of theOFF-clock signal OFF_CLK is N times the frequency f2 of the touchelectrode driving signal TDS (where N is a natural number), control canbe performed such that the voltage level of the touch electrode drivingsignal TDS does not vary in the high-level period Poff of the OFF-clocksignal OFF_CLK by setting the rising time point Tr2 of the touchelectrode driving signal TDS to be earlier than the rising time pointTr1 of the OFF-clock signal OFF_CLK.

According to the above-mentioned method, even when the frequency f1 ofthe OFF-clock signal OFF_CLK is 1/N times the frequency f2 of the touchelectrode driving signal TDS (where N is a natural number), control canbe performed such that the voltage level of the touch electrode drivingsignal TDS does not vary in the high-level period Poff of the OFF-clocksignal OFF_CLK by appropriately controlling the rising time point andthe falling time point of the touch electrode driving signal TDS and theOFF-clock signal OFF_CLK.

Similarly to the above-mentioned method, even when the frequency f1 ofthe OFF-clock signal OFF_CLK is 1/N times the frequency f2 of the touchelectrode driving signal TDS (where N is a natural number), control canbe performed such that the voltage level of the touch electrode drivingsignal TDS does not vary in the high-level period Pon of the ON-clocksignal ON_CLK by appropriately controlling the rising time point and thefalling time point of the touch electrode driving signal TDS and theON-clock signal ON_CLK.

On the other hand, when the frequency f1 of the ON-clock signal ON_CLKand the OFF-clock signal OFF_CLK is N or 1/N times the frequency f2 ofthe touch electrode driving signal TDS (where N is a natural number),control can be performed such that the voltage level of the touchelectrode driving signal TDS does not vary in the high-level period Ponof the ON-clock signal ON_CLK and the high-level period Poff of theOFF-clock signal OFF_CLK by controlling the rising/falling time pointsas described above, and thus duty ratio control of the touch electrodedriving signal TDS is not necessary.

Accordingly, when the frequency f1 of the ON-clock signal ON_CLK and theOFF-clock signal OFF_CLK is N or 1/N times the frequency f2 of the touchelectrode driving signal TDS (where N is a natural number), the touchelectrode driving signal TDS has a constant duty ratio.

FIGS. 27 and 28 are diagrams illustrating effects of the gate drivingcontrol illustrated in FIG. 23B in the touch display device, where FIG.27 is a diagram illustrating a situation in which a touch electrode TE2which is to be sensed and a gate line GL1 which is to be turned onoverlap each other and FIG. 28 is an equivalent circuit diagram of asubpixel which overlaps the touch electrode TE2 which is to be sensedand which is connected to the gate line GL1 which is to be turned onaccording to one embodiment.

Referring to FIG. 27, when display driving and touch driving aresimultaneously performed, the touch electrode driving signal TDS issupplied to the touch electrodes TE1, TE2, TE3, TE4, . . . . Here, thetouch electrode driving signal TDS is a signal for touch driving andalso serves as a common voltage signal for display driving.

When display driving and touch driving are simultaneously performed, thetouch driving circuit TDC senses all or some of the touch electrodesTE1, TE2, TE3, TE4, . . . to sense a touch. In the example illustratedin FIG. 27, one touch electrode TE2 of the touch electrodes TE1, TE2,TE3, TE4, . . . is to be sensed.

On the other hand, as described above, some gate lines GL1, GL2, GL3,GL4, which are arranged in the display panel DISP can overlap the touchelectrodes TE1, TE2, TE3, TE4, . . . which are arranged in the same row.

Accordingly, when display driving and touch driving are simultaneouslyperformed, a part (GL1 in the example illustrated in FIG. 27) of thegate lines GL1, GL2, GL3, GL4, . . . overlapping the touch electrode(TE2 in the example illustrated in FIG. 27) which is to be sensed out ofthe touch electrodes TE1, TE2, TE3, TE4, . . . is supplied with a scansignal of a turn-on level (Vgate1 in the example illustrated in FIG. 27)and is driven (turned on).

In FIG. 27, the scan signal Vgate1 of a turn-on level has a signalwaveform (the same signal waveform as the scan signal Vgate illustratedin FIGS. 17 and 18) for simultaneously performing display driving andtouch driving, but is illustrated as a signal waveform for performingonly display driving for the purpose of convenience of explanation andeasy understanding.

A transistor TR which is disposed in a subpixel SP illustrated in FIG.28 is turned on by a scan signal Vgate1 of a turn-on level which issupplied via a part GL1 of the gate lines GL1, GL2, GL3, GL4, . . .overlapping the touch electrode TE2 which is to be sensed out of thetouch electrodes TE1, TE2, TE3, TE4, . . . .

Equivalent circuits of all the other subpixels SP which are arranged onthe display panel DISP are the same as the equivalent circuit of thesubpixel SP illustrated in FIG. 28. The structure of the subpixel SPwill be described in brief with reference to FIG. 28. The subpixel SPincludes a transistor TR and a pixel electrode PXL.

The transistor TR in the subpixel SP includes a gate electrode connectedto the gate line GL1, a drain electrode (or a source electrode)connected to the data line DL, and a source electrode (or a drainelectrode) connected to the pixel electrode PXL.

The transistor TR in the subpixel SP is turned on in response to thescan signal Vgate1 which is supplied via the gate line GL1 and thustransmits a data signal Vdata which is supplied via the data line DL tothe pixel electrode PXL. The data signal Vdata transmitted to the pixelelectrode PXL may have the signal waveform illustrated in FIG. 17 or 18.

The pixel electrode PXL to which the data signal Vdata is transmittedcan form a storage capacitor Cst along with the touch electrode TE2 towhich the touch electrode driving signal TDS is supplied. Here, thestorage capacitor Cst is a capacitor which is required for storing avoltage for a predetermined time for display.

On the other hand, an internal capacitor Cgs can be formed between thegate electrode and the source electrode (or drain electrode) of thetransistor TR. A gate-touch capacitor Cgc can be formed between the gateelectrode of the transistor TR or the gate line GL1 and the touchelectrode TE2.

When display driving and touch driving are simultaneously performed andthe data signal Vdata illustrated in FIG. 17 or 18 is supplied to thepixel electrode PXL, change in charge ΔQ1 which is required for displaydriving is generated in the storage capacitor Cst. The change in chargeΔQ1 which is generated in the storage capacitor Cst is required fordisplay driving and is natural, but may be unnecessary for touchsensing.

Here, the change in charge ΔQ1 which is necessary for display drivingbut unnecessary for touch sensing in the storage capacitor Cst isgenerated by an original data voltage change part (PULSE2 in FIG. 17 andPULSE1 in FIG. 18) for display in the data signal Vdata. When the changein charge ΔQ1 which is necessary for display driving but unnecessary fortouch sensing is generated in the storage capacitor Cst as describedabove, a voltage variation which is unnecessary for touch sensing can begenerated in the touch electrode TE2 which is coupled to the pixelelectrode PXL via the storage capacitor Cst.

In other words, the original data voltage change part (PULSE2 in FIG. 17and PULSE1 in FIG. 18) for display in the data signal Vdata causes anundesired voltage variation in the pixel electrode PXL and thus anundesired voltage variation can be generated in the touch electrode TE2.The undesired voltage variation which is caused in the touch electrodeTE2 due to the voltage variation of the data signal Vdata can act asnoise at the time of touch sensing.

When display driving and touch driving are simultaneously performed, achange in charge ΔQ2 may occur in the gate-touch capacitor Cgc formedbetween the gate electrode of the transistor TR or the gate line GL1 andthe touch electrode TE2 due to a voltage variation (a voltage of aturn-off level <-> a voltage of a turn-on level) of the gate signalVgate1 which is supplied to the gate line GL1 or the transistor TRconnected thereto.

The change in charge ΔQ2 in the gate-touch capacitor Cgc formed betweenthe gate electrode of the transistor TR or the gate line GL1 and thetouch electrode TE2 is necessary and natural for display driving but maybe unnecessary for touch sensing.

Here, the change in charge ΔQ2 which is necessary for display drivingbut unnecessary for touch sensing in the gate-touch capacitor Cgc isgenerated by an original voltage change part (ΔVgate in FIGS. 17 and 18)for display in the gate signal Vgate1.

When the change in charge ΔQ2 which is necessary for display driving butunnecessary for touch sensing is generated in the gate-touch capacitorCgc as described above, a voltage variation which is unnecessary fortouch sensing can be generated in the touch electrode TE2 which iscoupled to the gate electrode of the transistor TR or the gate line GL1via the gate-touch capacitor Cgc.

In other words, the original voltage change part (ΔVgate in FIGS. 17 and18) for display in the gate signal Vgate1 causes an undesired voltagevariation in the touch electrode TE2. The undesired voltage variationwhich is caused in the touch electrode TE2 due to the voltage variationof the gate signal Vgate1 can act as noise at the time of touch sensing.

When display driving and touch driving are simultaneously performed andthe gate lines GL1, GL2, GL3, GL4, . . . overlapping the touch electrodeTE2 which is to be sensed out of the touch electrodes TE1, TE2, TE3,TE4, . . . are driven (turned on), the changes in charge ΔQ1 and ΔQ2 inthe storage capacitor Cst and the gate-touch capacitor Cgc act as noisecomponents at the time of touch sensing, and thus the data part acquiredfrom the touch electrode TE2 which is to be sensed out of touch sensingdata is an overflow value and may not have a meaning as sensing data. Asa result, touch sensing may not be normally carried out.

When display driving and touch driving are simultaneously performed asdescribed above, the changes in charge ΔQ1 and ΔQ2 which are necessaryand natural for display driving but act as noise for touch sensing canbe removed or decreased by the gate driving control illustrated in FIG.23B.

As described above with reference to FIG. 23B, in the touch displaydevice, the high-level period Pon of the ON-clock signal ON_CLK and thehigh-level period Poff of the OFF-clock signal OFF_CLK can correspond toeach other. That is, the high-level period Pon of the ON-clock signalON_CLK and the high-level period Poff of the OFF-clock signal OFF_CLKmay be temporally the same period or may be periods which partiallyoverlap each other temporally.

Accordingly, the falling section Pdown of the first scan signal Vgate1which is supplied to the first gate line GL1 out of the plurality ofgate lines GL can correspond to the rising section Pup of the third scansignal Vgate3 which is supplied to the third gate line GL3 other thanthe first gate line GL1 out of the plurality of gate lines GL.

Here, the first gate line GL1 and the third gate line GL3 differenttherefrom can overlap the same touch electrode TE2. One or more othergate lines GL2 may be disposed between the first gate line GL1 and thethird gate line GL3. On the other hand, the first gate line GL1 and thethird gate line GL3 may be neighboring gate lines.

Similarly, the falling section Pdown of the second scan signal Vgate2which is supplied to the second gate line GL2 out of the plurality ofgate lines GL can correspond to the rising section Pup of the fourthscan signal Vgate4 which is supplied to the fourth gate line GL4 otherthan the second gate line GL2 out of the plurality of gate lines GL.

Here, the second gate line GL2 and the fourth gate line GL4 differenttherefrom can overlap the same touch electrode TE2. One or more othergate lines GL3 may be disposed between the second gate line GL2 and thefourth gate line GL4. On the other hand, the second gate line GL2 andthe fourth gate line GL4 may be neighboring gate lines.

Referring to FIG. 23B, according to the above-mentioned gate drivingcontrol, when the first scan signal Vgate1 which is supplied to thefirst gate line Gll out of the gate lines GL1, GL2, GL3, GL4, . . .overlapping one touch electrode TE2 falls (gate OFF), the third scansignal Vgate3 which is supplied to the third gate line GL3 differentfrom the first gate line GL1 rises (gate ON) and thus a charge flow −Qwhich is caused in the capacitors Cst and Cgc associated with the touchelectrode TE2 due to the falling of the first scan signal Vgate1 and acharge flow+Q in the capacitors Cst and Cgc associated with the touchelectrode TE2 due to the rising of the third scan signal Vgate3 areopposite to each other.

By these charge flows+Q and −Q which are opposite to each other,influences of the unnecessary changes in charge ΔQ1 and ΔQ2 in thecapacitors Cst and Cgc associated with the touch electrode TE2 to thetouch electrode TE2 which is to be sensed can be cancelled. Accordingly,overflow of sensing data which is acquired from the touch electrode TE2which is to be sensed is reduced and touch sensitivity can be enhanced.

FIG. 29 is a flowchart illustrating a driving method of the touchdisplay device according to one embodiment.

Referring to FIG. 29, a driving method of the touch display deviceincludes a simultaneous driving step S10 and an image displaying andtouch sensing step S20.

In the simultaneous driving step S10, the touch display device canoutput the data signals Vdata and the scan signals Vgate to the datalines DL and the gate lines which are arranged in the display panel DISPand output the touch electrode driving signal TDS to one or more of aplurality of touch electrodes TE which are arranged in the display panelDISP.

In the image displaying and touch sensing step S20, the touch displaydevice can display an image in response to the data signal Vdata and thetouch electrode driving signal TDS and sense a touch on the basis of thesensing result of the touch electrode TE to which the touch electrodedriving signal TDS is supplied.

The voltage level of the touch electrode driving signal TDS can vary ina section other than the rising section Pup or the falling section Pdownof the scan signal Vgate.

According to the above-mentioned embodiments of the disclosure, it ispossible to provide a touch display device, a driving circuit, and adriving method that can simultaneously stably execute display drivingand touch driving.

According to the embodiments of the disclosure, it is possible toprovide a touch display device, a driving circuit, and a driving methodthat can simultaneously stably execute display driving and touch drivingusing a display panel having touch sensors embedded therein.

According to the embodiments of the disclosure, it is possible toprovide a touch display device, a driving circuit, and a driving methodthat can reduce an image defect of a line shape which may be caused bytiming mismatch between the gate driving relevant signals ON_CLK,OFF_CLK, GCLK, and Vgate and the touch electrode driving signal TDS.

The above description and the accompanying drawings exemplify thetechnical idea of the present disclosure, and various modifications andchanges such as combination, separation, substitution, and alteration ofconfigurations can be made by those skilled in the art without departingfrom the scope of the disclosure. Accordingly, the embodiments disclosedin the present disclosure are not to restrict the scope of thedisclosure but to explain the technical idea of the disclosure. Thescope of the disclosure is not limited to the embodiments. The scope ofthe disclosure is defined by the appended claims.

What is claimed is:
 1. A touch display device comprising: a display panel in which a plurality of data lines and a plurality of gate lines are arranged, a plurality of subpixels are arranged, and a plurality of touch electrodes are arranged; a display controller configured to output an ON-clock signal and an OFF-clock signal; a gate driving circuit configured to output a scan signal to the plurality of gate lines on a basis of the ON-clock signal and the OFF-clock signal; a data driving circuit configured to output a data signal for displaying an image to the plurality of data lines; and a touch driving circuit configured to supply a touch electrode driving signal to one or more of the plurality of touch electrodes, sense one or more of the plurality of touch electrodes, and output sensing data, wherein a voltage level of the touch electrode driving signal has a first voltage level during a first period and a second voltage level during a second period, the voltage level of the touch electrode driving signal is configured to be changed between the first voltage level and the second voltage level during a third period, and wherein an entire of a high-level period of the ON-clock signal and a high-level period of the OFF-clock signal are configured to be overlapped with the touch electrode driving signal during the first period or the second period.
 2. The touch display device according to claim 1, wherein the high-level period of the ON-clock signal and the high-level period of the OFF-clock signal correspond to each other and a low-level period of the ON-clock signal and a low-level period of the OFF-clock signal correspond to each other.
 3. The touch display device according to claim 1, wherein a falling section of a first scan signal which is supplied to a first gate line of the plurality of gate lines corresponds to a rising section of another scan signal which is supplied to another gate line other than the first gate line out of the plurality of gate lines.
 4. The touch display device according to claim 3, wherein the first gate line and the another gate line overlap a same touch electrode.
 5. The touch display device according to claim 1, wherein a frequency of the ON-clock signal and the OFF-clock signal is N or 1/N times a frequency of the touch electrode driving signal, wherein N is a natural number other than 0, and wherein the touch electrode driving signal has a constant duty ratio.
 6. The touch display device according to claim 5, wherein if the frequency of the OFF-clock signal is N times a frequency of the touch electrode driving signal, a rising time point of the touch electrode driving signal is set to be later than a falling time point of the OFF-clock signal, or the rising time point of the touch electrode driving signal is set to be earlier than the rising time point of the OFF-clock signal.
 7. The touch display device according to claim 1, wherein a frequency of the ON-clock signal and the OFF-clock signal is other than N or 1/N times a frequency of the touch electrode driving signal, wherein N is a natural number other than 0, and wherein the touch electrode driving signal has a variable duty ratio.
 8. The touch display device according to claim 7, wherein the touch electrode driving signal rises with a delay after the high-level period of the ON-clock signal and the high-level period of the OFF-clock signal have passed depending on adjustment of the duty ratio, and wherein the touch electrode driving signal falls before the high-level period of the ON-clock signal and the high-level period of the OFF-clock signal have started depending on adjustment of the duty ratio.
 9. The touch display device according to claim 1, wherein the voltage level of the touch electrode driving signal varies in a section other than a rising section or a falling section of the scan signal.
 10. The touch display device according to claim 1, wherein the touch driving circuit is configured to sense at least one of the plurality of touch electrodes when display driving is being executed by supplying the data signal for displaying an image to the plurality of data lines.
 11. The touch display device according to claim 1, wherein the touch electrode driving signal is a signal of which a voltage level varies periodically, wherein a period or a width of a high-level voltage period of the touch electrode driving signal is longer than one horizontal time for display driving, and wherein, in the period or the high-level voltage period of the touch electrode driving signal, a voltage level of the data signal for displaying an image which is supplied to at least one data line of the plurality of data lines varies one or more times, or a voltage level of the scan signal which is supplied to at least one gate line of the plurality of gate lines varies one or more times.
 12. The touch display device according to claim 1, wherein the touch electrode driving signal is a signal of which a voltage level varies periodically, wherein a period or a width of a high-level voltage period of the touch electrode driving signal is shorter than one horizontal time for display driving, and wherein, in the one horizontal time for display driving, the voltage level of the touch electrode driving signal varies one or more times.
 13. The touch display device according to claim 1, wherein the data driving circuit is configured to convert an image digital signal into an image analog signal in response to a gamma reference voltage, wherein the data driving circuit is configured to output the data signal corresponding to the image analog signal to the data lines, and wherein a frequency and a phase of the gamma reference voltage correspond to those of the touch electrode driving signal.
 14. The touch display device according to claim 1, wherein a ground voltage which is applied to the display panel is a modulated signal of which a frequency and a phase correspond to those of the touch electrode driving signal.
 15. The touch display device according to claim 1, wherein the touch display device is configured to independently perform display and touch sensing, wherein if the touch display device simultaneously performs display and touch sensing, the touch driving circuit supplies a first touch electrode driving signal of a variable voltage to the plurality of touch electrodes, wherein if the touch display device performs only display, the touch driving circuit supplies a second touch electrode driving signal of a DC voltage to the plurality of touch electrodes, and wherein if the touch display device performs only touch sensing, the touch driving circuit supplies a third touch electrode driving signal of a variable voltage to the plurality of touch electrodes.
 16. The touch display device according to claim 15, an amplitude of the first touch electrode driving signal is less than an amplitude of the third touch electrode driving signal.
 17. A touch display device comprising: a display panel in which a plurality of data lines and a plurality of gate lines are arranged, a plurality of subpixels are arranged, and a plurality of touch electrodes are arranged; a gate driving circuit configured to sequentially output a scan signal to the plurality of gate lines; a data driving circuit configured to output a data signal to the plurality of data lines; and a touch driving circuit configured to supply a touch electrode driving signal to one or more of the plurality of touch electrodes, wherein a voltage level of the touch electrode driving signal has a first voltage level during a first period and a second voltage level during a second period, the voltage level of the touch electrode driving signal is configured to be changed between the first voltage level and the second voltage level during a third period, and wherein at least one of a rising section of the scan signal and a falling section of the scan signal is configured to be overlapped with the touch electrode driving signal during the first period or the second period.
 18. The touch display device according to claim 17, wherein a falling section of a first scan signal which is supplied to a first gate line of the plurality of gate lines corresponds to a rising section of another scan signal which is supplied to another gate line other than the first gate line out of the plurality of gate lines.
 19. The touch display device according to claim 18, wherein the first gate line and the another gate line overlap a same touch electrode.
 20. A driving circuit comprising: a data driving circuit configured to output a data signal to data lines which are arranged on a display panel; and a touch driving circuit configured to drive one or more of a plurality of touch electrodes which are arranged on the display panel and output a touch electrode driving signal to one or more of the plurality of touch electrodes, wherein a voltage level of the touch electrode driving signal has a first voltage level during a first period and a second voltage level during a second period, the voltage level of the touch electrode driving signal is configured to be changed between the first voltage level and the second voltage level during a third period, and wherein at least one of a rising section and a falling section of a scan signal which is output to a plurality of gate lines which are arranged on the display panel is configured to be overlapped with the touch electrode driving signal during the first period or the second period.
 21. The driving circuit according to claim 20, wherein a falling section of a first scan signal which is supplied to a first gate line of the plurality of gate lines corresponds to a rising section of another scan signal which is supplied a gate line other than the first gate line out of the plurality of gate lines.
 22. A driving method of a touch display device including a display panel in which a plurality of data lines and a plurality of gate lines are arranged and a plurality of subpixels are arranged, the driving method comprising: outputting a data signal and a scan signal to the data lines and the gate lines which are arranged on the display panel and outputting a touch electrode driving signal to one or more of a plurality of touch electrodes which are arranged on the display panel; and displaying an image in response to the data signal and the touch electrode driving signal and sensing a touch on a basis of a result of sensing of the touch electrodes to which the touch electrode driving signal is supplied, wherein a voltage level of the touch electrode driving signal has a first voltage level during a first period and a second voltage level during a second period, the voltage level of the touch electrode driving signal is configured to be changed between the first voltage level and the second voltage level during a third period, and wherein at least one of a rising section and a falling section of the scan signal is configured to be overlapped with the touch electrode driving signal during the first period or the second period.
 23. The driving method according to claim 22, wherein a falling section of a first scan signal which is supplied to a first gate line of the plurality of gate lines corresponds to a rising section of another scan signal which is supplied to another gate line other than the first gate line out of the plurality of gate lines.
 24. The driving method according to claim 23, wherein the first gate line and the another gate line overlap a same touch electrode. 